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Th^  Students'  Quiz  Si^ips 


^^, 


AN A  TO  mT 


*%. 


A  MANUAL  FOR  STUDENTS  AND  PRACTITIONERS. 


BY 


FRED  J.  [brock WAY,  M.  D., 

Assistaiit  Demonstrator  of  Anatomy,  College  of  Physicians  and  Surgeons,  Neiv  York, 

AND 

A.  O'MALLEY,  M.  D., 

Instructor  in  Surgery,  New  Yoi'k  Polyclinic. 


SECOND  EDITION,  ^WITH  FULL-PAGE  PLATES. 


SERIES   EDITED  BY 

BERN  B.  GALLAUDET,  M.D., 

Demonstrator  of  Anatomy,  College  of  Physicians  and  Surgeons,  New  York  ;  Visiting 
Surgeon  Bellevue  Hospital,  New  York. 


QH2.2, 


PHILADELPHIA ; 
LEA  BROTHERS  &  CO. 


Entered  according  to  Act  of  Congress,  in  the  year  1893,  by 

LEA   BROTHERS  &  CO., 

In  the  Ofl&ce  of  the  Librarian  of  Congress,  at  Washington.    All  rights  reserved. 


Westcott  &  Thomson,  William  J.  Dornan, 

Stereoiypers  and  Electrotypers,  Philada.  Printer,  Philada. 


HENUY  I.  FLEISSia 


PREFACE. 


The  opportunity  aiForded  by  the  preparation  of  this  book  for 
the  presentation  of  a  brief  Modern  Anatomy  has  been  deemed  too 
valuable  to  sacrifice  by  duplicating  existing  "  Anatomical  Com- 
pends."  The  science  is  steadily  advancing  in  the  discovery  of 
new  facts.  Twenty  years  ago  the  German  anatomists  recorded  dis- 
coveries which  are  only  now  coming  to  the  notice  of  the  American 
student.  A  hand-book  can  at  most  contain  only  the  essentials  of 
the  science,  and  in  the  present  instance  the  effort  has  been  to 
select  such  knowledge  as  will  be  most  useful  to  the  student  and 
the  practitioner. 

In  the  hope  of  presenting  some  new  descriptions  not  acces- 
sible to  all  students,  I  have  compiled  the  sections  on  Osteology, 
Arthrology,  and  Myology  from  Henle  and  from  Quain,  while  Gray's 
Anatomy  and  notes  on  the  lectures  of  Prof.  George  S.  Huntington 
of  the  College  of  Physicians  and  Surgeons,  New  York,  have  also 
been  largely  consulted.  The  order  and  classification  of  Henle 
have  been  followed  throughout:  joints  are  mostly  from  his  work, 
and  where  his  descriptions  of  them  differ  greatly  from  those  of  Eng- 
lish text-books,  they  have  been  described  separately  in  fine  print. 
Many  muscular  anomalies  have  been  mentioned  in  fine  print. 
New  names  for  muscles  as  agreed  upon  by  the  German  Ana- 
tomical Society  have  been  marked  ^'  p.  n."  (proposed  name). 
Illustrations  from  Gray,  Quain,  Henle,  and  Schwalbe  have  been 
reproduced  to  illustrate  special  points.  English  and  metric  meas- 
urements are  both  given,  the  English  being  approximately  correct. 


IV  PREFACE. 

Space  has  been  gained  by  conciseness  and  by  the  omission  of  many 
monosyllabic  words.  It  is  to  be  noted  that  the  questions  are,  in 
a  sense,  headings  introducing  generally  a  large  amount  of  informa- 
tion in  the  answers. 

The  Glossary  has  been  written  in  the  hope  of  promoting  a  cor- 
rect pronunciation  of  anatomical  terms. 

I  have  to  acknowledge  the  assistance  of  Dr.  Andrew  O'Malley 
and  the  Editor  of  the  Series,  who  have  written  the  sections  on 
Angeiology,  Neurology,  and  Splanchnology.  In  the  latter  section 
the  relations  of  the  viscera  are  with  slight  modifications  those 
given  by  Professor  George  S.  Huntington,  and  the  works  of  Quain 
and  Gray  serve  as  the  basis  for  the  general  descriptions  of  the 
viscera,  as  well  as  for  the  sections  on  Angeiology  and  Neur- 
ology. 

This  volume  is  not  intended  to  replace  text-books,  but  will  be 
found  serviceable  in  facilitating  the  remembrance  of  knowledge 
gained  from  more  extended  works  and  at  the  dissecting-table. 

FRED  J.  BROCKWAY. 

105  W.  74th  St.,  \ 
New  York,     j 


lajBJNK.^^  I'  Fl^EISSia 


CONTENTS. 


PAGE 

Definition  and  Subdivisions  of  Anatomy 17 

Embryology 17 

Descriptive  Anatomy 19 


OSTEOLOGY. 

Bones  of  the  Trunk  :   The  Vertebral  Column ;   False  Vertebrae ; 

Ossification  of  the  Vertebrae ;  The  Thorax ;  The  Hyoid  Bone  .  .  23 
Bones  of  the  Head  :  Bones  of  the  Cranium ;  Bones  of  the  Face ; 

The  Skull  as  a  Whole ;  The  Wormian  Bones ;  External  Surface 

of  the  Skull ;  Ossification  of  the  Bones  of  the  Head  ......      35 

Bones  of  the  Upper  Extremity  :  The  Shoulder ;  The  Arm ;  The 

Forearm;  The  Hand 64 

Bones  of  the  Lower  Extremity  :  The  Pelvis ;  The  Thigh ;  The 

Leg;  The  Foot 76 


AKTHKOLOGY. 

Henle's  Classification  of  Joints 93 

Articulations  of  the  Trunk  and  Head  :  Henle's  Vertebral  and 

Costal  Ligaments 95 

Articulations  of  the  Upper  Extremity:  The  Shoulder-girdle 

and  Joint ;   The  Elbow  and  Forearm  ;   The  Wrist  and  Carpus ; 

Accessory  Ligaments  of  the  Wrist 104 

Articulations  of  the  Lower  Extremity:  The  Pelvic  Girdle; 

Ligaments  between  tlie  Bones  of  the  Trunk  and  Hip-bone ;  The 

5 


6  CONTENTS. 

PAGE 

Hip-joint;  The  Knee-joint;  Ligaments  between  the  Bones  of 
the  Leg;  The  Ankle-joint;  Joints  of  the  Foot;  Heule's  Classi- 
fication of  the  Ankle-  and  Foot-joints 120 

MYOLOGY. 

Muscles  in  General 138 

Muscles  of  the  Trunk  :  Muscles  and  Fasciae  of  the  Back  ;  Muscles 
and  Fasciae  of  the  Abdomen;  Lining  Fasciae  of  the  Abdomen; 
Muscles  and  Fasciae  of  the  Chest;   Muscles  and  Fasciae  of  the 

Neck ;  Muscles  of  the  Head 139 

Muscles  and  Fascia  of  the  Extremities: 173 

The  Upper  Extremity :  The  Shoulder ;  The  Upper  Arm ;  The  Fore- 
arm ;  The  Hand 173 

The  Lower  Extremity:  The  Hip  and  Thigh  ;  The  Leg;  The  Foot  .    .    186 
Muscular  Homologies 202 

ANGEIOLOGY. 

The  Heart:  Structure  of  the  Heart 204 

Arteries:  The  Pulmonary  Artery 208 

Systemic  Arteries:  Arch  of  the  Aorta  and  its  Branches;  Arteries 
of  the  Head,  Neck,  and  Upper  Extremity ;  The  Thoracic  Aorta 
and  its  Branches;  Tlie  Abdominal  Aorta  and  its  Branches;  The 
Iliac  Arteries  and  their  Branches;  Arteries  of  the  Lower  Ex- 
tremity and  their  Branches 208 

Veins  :  The  Pulmonary  Veins 233 

Systemic  Veins:  Superior  Vena  Cava  and  Innominate  Veins;  Veins 
of  the  Head  and  Neck ;  Veins  of  the  Upper  Extremity ;  Veins 
of  the  Trunk ;  Veins  of  Lower  Extremity ;  Veins  of  the  Pelvis ; 

The  Portal  System 233 

The  Absorbent  System 245 

NEUROLOGY. 

The  Spinal  Cord 249 

The  Brain  or  Encephalon 252 


CONTENTS.  / 

PAGE 

Cranial  Nerves 266 

The  Spinal  Nerves 277 

The  Sympathetic  Nervous  System 292 

Organs  of  Special  Sense:  The  Eye;  The  Ear;  The  Nose;  The 

Tongue 297 


SPLANCHNOLOGY. 

Organs  of  Respiration  :  The  Larynx  ;  The  Trachea ;  The  Thyroid 

and  Thymus  Glands ;  Pleurae  and  Mediastinum  ;  The  Lungs  .    .    310 

The  Organs  of  Digestion  :  The  Mouth ;  The  Teeth ;  The  Palate ; 
The  Tonsils;  The  Salivary  Glands;  The  Pharynx;  The  CEsopha- 
gus;  The  Stomach;  The  Small  Intestine;  The  Large  Intestine; 
The  Liver ;  The  Gall-bladder ;  The  Pancreas 318 

The  Spleen  and  Suprarenal  Capsules  :  The  Spleen ;  The  Supra- 
renal Capsules 335 

The   Urinary  Organs   and   Peritoneum  :    The  Kidneys ;    The 

Ureters;  The  Bladder;  The  Peritoneum 336 

Organs   of   Reproduction   (Male)  :    The   Prostate   Gland ;   The 

Penis ;  The  Male  Urethra ;  The  Testes 342 

Organs  of  Reproduction  (Female) 348 

External:  The  Vulva;  The  Vagina 348 

Internal :  The  Uterus ;   The  Fallopian  Tubes ;   The  Ovaries ;  The 

Parovarium 349 

The  Mammary  Glands   .        352 


ANATOMY. 


DEFINITION  AND  SUBDIVISIONS   OF  ANATOMY. 
What  are  the  object  and  subdivisions  of  anatomy  ? 

Its  object  is  to  find  out  the  structure  of  organized  bodies.  This  sci- 
ence includes  Human,  Comparative,  and  Vegetable  Anatomy. 

The  animal  possesses  two  tubes,  the  animal  and  vegetative :  the  former 
contains  the  spinal  cord  and  brain,  distinguishing  in  part  the  animal 
from  the  plant ;  the  vegetative  tube  is  common  to  both,  and  encloses  the 
organs  of  nutrition  and  reproduction. 

Human  Anatomy  is  subdivided  into  Histology,  or  General  Anatomy, 
and  Descriptive,  or  Special  Anatomy.  The  following  pages  treat  of 
Descriptive  xAnatomy. 

EMBRYOLOGY. 
Briefly  describe  the  process  of  development. 

The  human  ovum  is  a  small  cell,  j^th  inch  in  diameter ;  its  wall  is 
the  vitelline  membrane^  its  body  the  yolk^  its  nucleus  the  germinal  vesicle^ 
and  its  nucleplus  the  germinal  spot.  If  all  the  food-yolk  undergoes 
changes,  as  in  mammals,  the  ovum  is  holohlastic ;  if  only  part,  as  in 
fishes,  it  is  merohlastic.  When  the  ovum  matures  the  germinal  vesicle 
divides  and  extrudes  two  polar  globules;  inside  the  yolk  is  formed  a 
female  pronucleus. 

These  changes  occur  whether  the  ovum  is  fecundated  or  not.  Should 
another  cell,  the  spermatozoon^  enter  the  yolk,  its  tail  disappears  and  its 
head  becomes  the  male  pronucleus.  The  union  of  the  two  pronuclei 
forms  the  first  segmentation  sp^hei^e.  Halves  are  formed  of  this  sphere, 
each  one  again  splits,  and  so  on :  when  about  ninety -six  cells  are  formed, 
an  upper  group  of  sixty-four  will  completely  enclose  a  lower  group  of 
thirty-two. 

The  outer  group  lines  the  vitelline  membrane,  and  from  it  comes  the 
primitive  ectoderm,  the  epihlast  or  serous  layer.  From  the  enclosed 
group  comes  the  primitive  entoderm,  the  hypoblast  or  mucous  layer ;  be- 
tween them  is  later  developed  the  primitive  mesoderm.,  the  mesoblast  or 
vascular  laj^er.  On  the  outer  layer  there  appears  a  shaded  patch,  the 
area  germinativa,  and  in  this  come  in  order  (1)  the  primitive  streak,  (2) 
the  medullary  canal,  (3)  the  chorda  dorsalis  or  notochord,  and  (4)  the 
2— A.  17 


18  ANATOMY. 

mesohlastic  somites :  the  first  is  transient ;  the  third,  round  which  the 
vertebral  column  forms,  is  more  persistent;  the  second  and  fourth  are 
permanent.     The  primitive  streak  soon  acquires  a  primitive  groove. 

The  medullary  or  neural  canal  is  confined  to  the  epiblast,  and  formed 
by  two  lateral  ridges  meeting  dorsally.  The  chorda  dorsalis  is  a  thicken- 
ing of  the  hypoblast,  and  its  remains  are  the  centres  of  the  interverte- 
bral disks.  The  lateral  mesoblast  cleaves  into  two  plates :  one  clings  to 
the  epiblast,  forming  the  somatojyleure ;  the  other  to  the  hypoblast,  form- 
ing the  splanchnopleure.  The  former  forms  part  of  the  wall  of  the 
body,  the  latter  part  of  the  wall  of  the  alimentary  tract,  and  between 
the  two  is  the  coeJom,  or  pleuro-peritoneal  cavity. 

In  the  paraxial  mesoblast,  in  the  region  which  afterward  becomes  the 
neck,  is  developed  a  linear  series  of  quadrangular  masses,  the  meso- 
hlastic somites. 

At  the  anterior  end  of  the  neural  groove  are  formed  three  primary 
cerebral  vesicles ;  later  the  anterior  and  posterior  divide  each  into  two, 
making  five  in  all. 

The  steps  to  be  noted  are — (1)  formation  of  polar  globules  and  the 
male  and  female  pronuclei ;  (2)  segmentation  of  yolk ;  (3)  arrangement  of 
cells  inside  the  vitelline  membrane  into  two  groups ;  (4)  separation  of 
cells  into  epiblast,  mesoblast  (two  layers),  and  hyjjoblast;  (5)  formation 
of  area  germinativa;  (6)  primitive  trace;  (7)  primitive  groove  caused 
by  heaping  up  of  "dorsal  plates;"  (8)  neural  canal^  formed  by  the 
meeting  of  dorsal  plates;  (9)  under  this  canal  formation  of  notochord 
from  hypoblast;  (10)  a  line  of  square  segments,  the  mesohlastic  plates; 
(11)  somatopleure  and  splanchnopleure  and  body-cavity;  (12)  three 
primary  cerebral  vesicles ;  (13)  curving  of  the  embryo  longitudinally  and 
laterally,  comparable  to  a  canoe,  the  body-cavity  corresponding  to  the 
well  of  the  canoe ;  (14)  the  yolk-sac  outside  the  'body-cavity  is  the  um- 
bilical vesicle,  providing  nutrition  until  the  placenta  is  formed. 

What  parts  are  derived  from  each  blastodermic  layer  ? 

From  epiblast^  the  whole  nervous  system,  brain,  spinal  cord,  peripheral 
and  sympathetic  nerves;  epithelial  structures  of  the  organs  of  special 
sense ;  epidermis  and  appendages,  as  hair  and  nails ;  epithelium  of  glands 
which  open  upon  the  skin  surface,  as  mammary,  sweat,  and  sebaceous 
glands ;  muscular  fibres  of  sweat-glands ;  epithelium  of  mouth,  except 
that  covering  tongue,  and  of  glands  opening  into  it ;  enamel  of  teeth ; 
epithelium  of  nasal  passages  and  of  glands  and  cavities  opening  into 
them.  • 

From  mesoblast^  genito-urinary  organs,  except  epithelium  of  bladder 
and  urethra;  all  voluntary  and  involuntary  muscles,  except  muscular 
fibres  of  sweat-glands ;  vascular  and  lymphatic  systems ;  serous  mem- 
branes and  spleen ;  skeleton  and  all  connective-tissue  structures  of  body. 

From  hypoblast^  epithelium  of  alimentary  canal  from  back  of  mouth 
to  anus,  and  of  glands  which  open  into  this  part  of  the  tube ;  epithelium 
of  Eustachian  tube  and  tympanum ;  epithelium  of  bronchial  tubes  and 


OSTEOLOGY.  19 

air-sacs  of  lungs ;  epithelium  of  the  vesicles  of  the  thyroid ;  epithelial 
nests  of  the  thymus ;  epithelium  of  urinary  bladder  and  urethra. 

DESCRIPTIVE  ANATOMY. 
What  are  the  systems  of  descriptive  anatomy? 

1 .  Osteology,  the  bones ;  2.  Arthrology,  the  articulations ;  3.  IMyol- 
ogy,  the  voluntary  muscles,  fasciae,  and  aponeuroses ;  4.  Angeiology,  the 
heart,  blood-vessels,  and  lymphatics ;  5.  Neurology,  spinal  cord,  brain, 
nerves,  and  organs  of  the  senses ;  6.  Splanchnology,  the  organs  of  res- 
piration, digestion,  reproduction,  and  urination. 

An  organ  is  capable  of  isolation :  organs  make  up  a  S3^stem,  and  sys- 
tems an  apparatus. 

What  are  some  of  the  descriptive  terms  ? 

The  body  is  always  supposed  to  stand  erect,  with  hands  at  the  sides 
and  palms  to  the  front.  Superior  and  inferior  correspond  to  cephalic 
and  caudal^  anterior  and  posterior  to  ventral  and  dorsal.  As  the  body 
is  bilaterally  s^^mmetrical,  it  may  be  divided  into  similar  halves  by  a 
median  plane  passing  from  before  backward.  The  line  along  which  this 
plane  meets  the  surface  of  the  body  is  the  median  line.  The  words  in- 
ternal and  external  refer  to  points  nearer  to  or  farther  from  the  median 
plane.  Henle  uses  median  for  internal,  and  lateral  for  external ;  the 
ibrmer  looks  toward  the  median  line,  the  latter  from  it. 

Sagittal  denotes  an  antero-posterior  direction  in  or  parallel  to  the 
median  plane  ;  coronal  or  frontal  denotes  a  transverse  direction  at  right 
angles  to  the  sagittal.  Other  terms  applied  to  surfaces  or  borders,  like 
vertebral.,  sternal^  radial.,  idnar^  flexor,  extensor,  proximal  (nearest  the 
trunk  or  centre),  distal  (away  from  the  trunk),  are  often  convenient. 

A  surface  is  said  to  "  look  "  in  a  certain  direction  when  a  perpendic- 
ular to  the  surface  points  in  that  direction. 

OSTEOLOGY. 

What  is  the  skeleton  ? 

The  skeleton  is  the  sohd  framework  of  the  body,  composed  of  bones 
completed  by  cartilage.  In  the  lower  animals  there  may  be  an  endo- 
skeleton,  the  deeper  framework  corresponding  to  the  human  skeleton, 
and  an  exoskeleton,  comprising  the  integument  and  hardened  structures 
connected  with  it.  All  vertebrate  animals  possesses  an  endoskeleton ; 
some  have  an  exoskeleton.  Most  invertebrate  animals  possess  an  exo- 
skeleton  only. 

What  are  the  uses  of  bones  ? 

(1)  They  serve  as  levers  upon  which  attached  muscles  act ;  (2)  sup- 
port ;  (3)  protection  of  delicate  organs  ;  (4)  contribute  to  the  formation 
of  joints ;  (5)  by  elasticity  of  curvature  tend  to  diminish  shocks. 


20  OSTEOLOGY. 

How  are  bones  formed  ? 

They  are  formed  by  ossification  in  three  ways:  (1)  in  cartilage,  not 
from  it;  (2)  in  membrane;  (3)  subperiosteally. 

The  bones  of  the  vertex  of  the  skull — i.  e.  the  parietals,  the  frontal, 
the  tabular  part  of  the  occipital,  the  squamous  and  tympanic  parts  of 
the  temporal,  the  inner  plate  of  the  pterygoid  process,  the  bones  of  the 
face  except  the  inferior  turbinate  and  part  of  the  lower  jaw— are  formed 
in  membrane.  The  base  of  the  skull  and  the  other  bones  of  the  body 
are  formed  in  cartilage.  A  deposit  of  bone  begins  at  one  spot,  the 
primary  centre ;  the  shaft  or  diaphysis  is  formed  from  this.  Most  bones 
have  other  centres  of  ossification,  secondary^  or  tertiai^^  and  parts  de- 
rived from  them  are  the  epiphyses  [growing  upon).  The  growth  of 
bone  in  length  depends  largely  upon  the  cartilage  between  the  epiphysis 
and  diaphysis ;  this  cartilage  acts  as  a  bufier  in  concussions.  The  growth 
in  circumference  is  by  subperiosteal  ossification. 

Some  bones  ossify  early,  according  to  their  function — e.  g.  the  lower 
iaw  and  ribs,  because  suction  and  respiration  come  into  play  at  birth. 
The  first  primary  centre  to  appear  is  in  the  clavicle,  at  the  fifth  week  of 
foetal  life ;  the  last  secondary  centre  to  appear  is  in  the  sternal  end  of 
the  clavicle,  at  the  eighteenth  year.  At  birth  nearly  all  primary  centres 
have  appeared  (the  pisiform  not  till  the  twelfth  year),  and  only  one 
secondary  centre — viz.  that  for  the  lower  extremity  of  the  femur,  pos- 
sibly one  for  the  upper  extremity  of  the  tibia. 

What  are  the  rules  for  the  direction  of  medullary  arteries  ? 

1.  The  medullary  arteries  r\mfrom  the  knee  and  toward  the  elbow.  2. 
The  secondary  centre /ro?7i  which  the  artery  runs  is  t\iQ  first  to  appear. 
3.  The  epiphysis ^/'.sf  to  appear  is  la^'it  to  unite  (except  in  case  of  fibula, 
where  its  lower  epiphysis  appears  first  and  unites  first).  If  there  is  but 
one  secondary  centre  in  a  bone,  the  artery  runs  from  it.  Rule  1  may 
be  remembered  by  flexing  the  knees  and  elbows,  and  noting  that  the 
medullary  arteries  run  down  as  though  impelled  by  gravity. 

The  obliquity  of  the  vascular  canals  is  really  due  to  the  inequality  of 
growth  of  the  two  ends :  the  one  growing  more  rapidly  carries  the  artery 
with  it. 

Briefly  describe  the  structure  of  bone. 

This  description  includes  that  of  the  periosteum,  marrow,  and  bone 
proper. 

The  periosteum,  or  bone-skin,  consists  of  two  layers,  an  outer  fibrous 
and  an  mner  vascular  one,  beneath  which  are  granular  cells  called  osteo- 
blasts. The  periosteum  serves  as  a  nidus  for  vessels,  and  is  related  to 
the  growth  and  renewal  of  bone.  It  is  looser  on  young  bone  than  on 
old,  and  looser  on  the  shaft  than  on  the  extremities.  The  dura  mater  of 
the  brain  is  allied  to  periosteum. 

The  marrow  fills  the  medullary  canal,  cancellous  spaces,  and  large 


OSTEOLOGY.  21 

Haversian  canals.  The  medullary  canal  is  lined  with  endosteum. 
Marrow  may  be  yellow  or  red:  the  former  is  in  adult  long  bones 
and  contains  96  per  cent.  fat.  In  the  short  and  flat  bones,  in  the 
cancellated  ends  of  long  bones,  in  the  bodies  of  the  vertebrae,  in  the 
cranial  diploe,  in  the  sternum  and  ribs,  and  in  all  bones  of  the  foetus 
and  infant,  the  marrow  is  red  and  fluid,  containing  72  per  cent,  water 
and  a  trace  of  fat.  Marrow  may  possess  five  kinds  of  cells:  (I)  fat- 
cells;  (2)  marrow-cells  proper,  resembling  white  blood-cells,  and  possess- 
ing amoeboid  movement;  (3)  small  nucleated  reddish  cells;  (4)  cells 
containing  one  or  two  red  blood-corpuscles ;  (5)  giant-cells  (osteoclasts  or 
myeloplaxes),  which  are  concerned  with  bone-absorption.  Marrow  may 
help  form  and  renovate  blood,  form  bone,  and  has  nutritive  properties. 

Bone  proper  may  be  compact  or  cancellous ;  the  separate  cancelli  have 
the  same  structure  as  the  compact  bone.  Long  bones  have  an  outer 
shell  of  compact  substance,  spongy  tissue  at  the  ends,  with  a  dense  layer 
beneath  the  articular  cartilage,  and  a  medullary  canal. 

Flat  bones  have  two  compact  plates  enclosing  a  spongy  layer,  the 
diploe. 

Solid  bone  is  made  up  of  Haversian  systems  (Havers,  an  English  phy- 
sician). A  central  hole  is  the  Haversian  canal,  ^^Jx)  inch  in  diameter,  and 
five  to  fifteen  concentric  rings  around  it  are  the  lamellce.  Between  the 
lamellae  are  dark  specks,  the  lacunce^  which  are  connected  with  each  other 
and  the  central  canal  by  fine  lines,  the  canaliadi  Lamellae  may  be  con- 
centrtc,  around  Haversian  canals;  interstitial ,  between  Haversian  sys- 
tems; and  circumferential,  surrounding  the  bone.  The  canals  connect 
the  medullary  cavity  with  the  surface  of  the  bone,  allowing  free  permea- 
tion of  blood-vessels. 

The  lamellae  may  be  stripped  up  as  thin  films,  and  seem  bolted  together 
by  the  perforating  fibres  of  Sharpey.  In  thin  plates  of  bone  there  are 
no  Haversian  canals,  but  lacunae  and  canaliculi  are  present. 

What  is  the  arrangement  of  the  vascular  and  nerve  supply  ? 

The  arteries  are  periosteal,  articular,  and  medullary  (all  are  nutrient). 
The  veins  emerge  from  the  bone  in  the  same  places  that  the  arteries 
enter.  Lymphatics  accompany  the  vessels.  Nerves  enter  with  the  arte- 
ries, and  are  destined  for  the  vessels :  none  are  known  to  end  in  bony 
tissue  itself 

What  is  the  purpose  of  the  medullary  cavity? 

To  allow  greater  surface  for  muscular  attachment  with  economy  of 
weight ;  for  strength,  a  hollow  cylinder  being  stronger  than  a  solid  one 
of  same  weight.  In  some  water  animals  the  bones  are  nearly  solid,  act- 
ing as  ballast.  In  birds  the  bones  are  light,  with  large  medullary  cavities 
filled  with  warm  air  from  the  lungs.  In  the  human  subject  there  are 
air-cells  in  a  few  bones. 


22  OSTEOLOGY. 

What  are  the  physical  and  chemical  characters  of  bone  ? 

Bone  consists  one-third  of  animal  matter,  giving  tenacity  and  elasticity, 
impregnated  with  earthy  salts,  two-thirds,  in  the  form  of  minute  gran- 
ules :  this  gives  rigidity  and  brittleness.     The  analysis  by  Lehman  is — 

Gelatin  and  blood-vessels, 33  per  cent. 

Phosphate  of  calcium, 57        " 

Carbonate  of  calcium, 8        " 

Fluoride  of  calcium, 1         " 

Phosphate  of  magnesium, 1        " 

100  per  cent. 

Some  add  1  per  cent,  of  oily  matter. 

Pure  bone  is  thought  to  be  a  definite  compound,  whether  from  a  child 
or  old  person  :  it  differs  in  compactness  and  arrangement.  The  petrous 
portion  of  the  temporal,  and  the  long  bones  as  a  whole,  have  an  excess  of 
inorganic  matter  compared  with  bones  of  the  trunk — the  upper  extremity 
more  than  the  lower.  In  rickets  the  earthy  matter  may  sink  to  20  per 
cent. ,  instead  of  66  per  cent.  Calcium  phosphate  forms  more  than  half 
of  bone  and  88  per  cent,  of  enamel  of  teeth.  Bone  is  twice  as  strong 
as  oak,  three  times  as  strong  as  elm,  and  twenty- two  times  as  strong  as 
freestone.  A  cubic  inch  will  support  5000  pounds  weight ;  it  requires  800 
or  900  pounds  to  fracture  the  femur. 

What  is  the  number  of  bones  in  the  human  skeleton  ? 

200  in  the  adult ;  thus : 

K'  P---  Total. 

r  The  vertebral  column 26  .  .  26 

..,,,,                        The  skull -    ...    6  8  22 

Axial   skeleton,    ...  ^  The  hyoid  bone 1  .  .  1 

[  The  ribs  and  sternum 1  12  25 

Amiendicular  skeleton    [  The  upper  limbs .32         64 

Appenaicular  skeleton,  I  ^j^^  j^^^^  jjj^^g  ^         3^        ^^ 

34        83      200 

The  patella  and  pisiform  are  included,  but  not  the  ossicles  of  the  ear  or 
small  sesamoid  bones :  the  teeth  belong  to  the  epidermal  layer. 

Into  what  classes  are  hones  divisible? 

(1)  Long  or  cylindrical^  about  90  in  number;  (2)  tabular  ov flat,  for 
protection  or  muscular  attachment,  numbering  40 ;  (3)  sliort,  for  strength, 
numbering  30 ;  (4)  irregnlar,  mostly  situated  symmetrically  across  the 
median  plane  of  the  body,  numbering  40. 

Mention  some  terms  used  in  descriptions. 

There  are  eminences  and  depressions,  an  articular  and  non-articular 
subdivision,  of  each  variety. 

Articular  eminences  are  called  heads  and  condyles ;  non-articular  emi- 


BONES   OF   THE   TRUNK.  23 

nences  are  epicondyles,  trochanters,  tuberosities,  tuherdes,  spines,  lines, 
apophyses,  etc.  An  apophj^sis  (excrescence)  has  never  been  separate 
from  the  surface  of  bone ;  an  epiphysis  is  developed  from  a  separate 
centre. 

Certain  adjectives  used  are — cHnoid,  Hke  a  bed  ;  coracoid,  Hke  a  crow's 
beak ;  coronoid,  the  tip  of  a  curve ;  hamnlar,  like  a  hook ;  malleolar, 
like  a  mallet ;  mastoid,  like  a  nipple  ;  odontoid,  like  a  tooth  ;  pterygoid,  ^ 
like  a  wing ;  spinous,  thorn-like ;  styloid,  like  a  pen ;  vaginal,  ensheathing. 

Articular  cavities  are  cotyloid,  like  a  deep  cup ;  glenoid,  like  a  shallow 
cup ;  trochlear,  pulley-like ;  sigmoid,^  like  the  Greek  letter  for  s. 

Non-articular  cavities  are  fossae,  sinuses,  fissures,  grooves,  canals,  hia- 
tuses, etc. 

BONES  OF  THE  TRUNK. 

The  clavicle  and  scapula  do  not  belong  to  the  trunk ;  they  form  the 
shoulder  girdle. 

The  OS  innominatum  goes  to  form  the  pelvic  girdle,  completed  behind 
by  the  sacrum,  which  belongs  to  the  trunk.  The  animal  tube  is  enclosed 
by  the  vertebral  column ;  the  vegetative  tube  is  in  front  of  this  and  be- 
hind the  hyoid  bone  and  sternum.  The  parts  of  the  trunk  are  the  ver- 
tebral column,  the  sternum  and  ribs,  the  hyoid,  and  bones  of  the  skull. 

THE  VERTEBRAL,  COLUMN. 

1.  The  vertebral  column  is  composed  of  a  series  of  vertebrae  (verto,  to 
turn),  originally  thirty-three  in  number.  The  upper  twenty-four  reniai'n 
separate  as  movable  or  true  vertebrae ;  these  are  succeeded  by  five  united 
into  the  sacrum ;  then  follow  four  dwindled  segments  united  into  the 
coccyx.     These  lower  nine  are  the  fixed  or  false  vertebrae.  * 

Beginning  at  the  skull,  there  are  seven  cervical,  twelve  dorsal  or 
thoracic  connected  with  ribs,  five  abdominal  or  lumbar,  five  sacral,  and 
four  coccygeal  vertebrae.  The  number  in  the  cervical  region  is  constant ; 
those  between  the  dorsal  and  lumbar  may  vary  reciprocally.  If  there 
are  but  eleven  pairs  of  ribs,  the  twelfth  dorsal  vertebra  will  have  lumbar 
characteristics;  if  thirteen  pairs,  the  first  lumbar  will  have  dorsal  cha- 
racteristics. A  transitional  lumbosacral  vertebra,  is  met  with,  one  side 
connected  with  the  sacrum,  the  other  having  a  free  transverse  process. 

Describe  the  characteristics  of  a  vertebra. 

The  first  two  cervical  vertebrae  are  called  rotation  vertebrae ;  all  the 
other  true  ones,  flexion  vertebrae.  A  representative  vertebra,  like  the 
tenth  dorsal,  presents  a  body  for  the  purpose  of  support,  an  arch  and 
spinal  foramen  for  protection,  and  seven  processes  for  leverage.  The  body 
or  centrum,  is  a  short  cylinder ;  the  superior  and  inferior  surfaces  are  flat, 
with  a  rim  around  the  circumference.  The  front  and  sides  are  convex 
horizontally  and  concave  from  above  down.     The  posterior  surface  is 


24  BONES   OF   THE   TRUNK. 

slightly  concave  from  side  to  side,  and  marked  by  one  or  two  venous 
foramina.  The  neural  arch  consists  of  two  symmetrical  portions  meet- 
ing in  the  median  plane  behind.  The  anterior  part  or  pedicle  rises  from 
a  point  on  the  body  where  the  lateral  and  posterior  surfaces  meet ;  the 
posterior  part  or  lamina  is  broad  and  flat.  The  upper  and  lower  borders 
of  pedicles  form  vertebral  notches,  becoming  intervertebral  foramina 
-between  contiguous  vertebrae.  The  spinous  process  projects  back  from 
the  junction  of  the  two  laminae.  The  transverse  processes,  one  on  either 
side,  project  outward  from  the  arch  at  the  junction  of  the  pedicle  with 
the  lamina.  The  articular  processes^  two  superior  and  two  inferior, 
project  upward  and  ^wnward  at  the  point  of  origin  of  the  transverse 
processes.  *    ■ 

The  foramen  is  bounded  anteriorly  by  the  body,  posteriorly  and  later- 
ally by  the  arch;  the  series  of  rings  thus  formed  constitutes  the  spinal 
canal. 

Describe  a  cenrfcal  vertebra. 

The  body  is  small  and  broad  transversely ;  the  upper  surface  is  con- 
cave from  the  upward  projection  of  lateral  lips,  and  is  sloped  down  in 
front.  The  under  surface  is  rounded  at  the  sides  and  lipped  anteriorly, 
so  there  is  interlocking  at  the  sides  to  prevent  lateral  displacement — an 
anterior  lip  to  prevent  posterior,  and  articular  processes  to  prevent 
anterior,  dislocations.  The  laminae  are  long  and  flat.  The  superior  and 
inferior  notches  are  nearly  equal  in  depth.  The  spinous  processes  are 
short  and  bifid.  The  transverse  processes  are  directed  outward,  down- 
ward, and  forward,  and  present  at  their  extremities  an  anterior  and 
a  posterior  tubercle.  Each  process  is  grooved  above,  and  perforated 
vertically  at  its  base  by  the  vertebrarterial  foramen  for  a  vein,  artery,  and 
plexus  of  nerves.  This  foramen  is  between  the  two  roots  of  the  process, 
the  posterior  corresponding  to  a  dorsal  transverse  process,  and  the 
anterior  to  a  rib.  The  articular  processes  are  placed  at  the  extremities 
of  a  short  vertical  column  of  bone ;  the  superior  articular  surface  looks 
back  and  up.  The  foramen  is  triangular,  and  larger  than  in  any  other 
region.  The  peculiar  cervical  vertebrae  are  the  first,  second,  and 
seventh. 

Describe  the  atlas. 

The  atlas  (supporting  globe  of  head)  has  no  body  or  spinous  process, 
but  is  a  large  ring  with  articular  and  transverse  processes.  The  pos- 
terior part  of  the  ring  corresponds  to  the  neural  canal  of  the  other  ver- 
tebrae ;  the  anterior  part  is  occupied  by  the  odontoid  process  of  the  axis. 
The  anterior  boundarj^  of  the  ring  is  the  anterior  arch,  with  a  small 
tubercle  in  front  for  the  longus  colli  muscle.  Behind  the  tubercle  is  an 
articular  surface  for  the  odontoid.  At  the  sides  of  the  ring  are  the 
lateral  masses  bearing  the  superior  and  inferior  articular  processes.  All 
the  articular  processes  of  the  atlas  and  the  superior  ones  of  the  axis  are 
in  front  of  the  vertebral  notches.     The  superior  articular  surfaces  of  the 


PLATE  I. 
Fig.  l.—To  face  page  ^4- 


Ant.  tub.  of  trans- 
verse process. 
For.  for  vertebral, 
artery. 
Pos.  tub.  of  tr 

process. 


Transverse  process. 


I  process.  ^)      ^,^V^ 
Cervical  Vertebra.   ^*f>^  ^^V 


Fig.  2. — To  face  page  24- 
Tuber  cle.- 


Biagram  of  section  of 
odontoid  process. 

Diagram  of  section  of 
transverse  ligament. 


For.  for 
vertebral 


\artery. 


Groove  for  vertebral 
'artery  and  1st 
cervical  nerve. 


Rudimentary  spinous  process. 


The  Atlas. 


Fig.  ^.— To  face  page  81. 
By  4  primary  centimes. 

for  body  {8th  week). 


Ifor  each  lamina  (6th  weeTc). 


PLATE  II. 

Fig.  1. — To  face 'page  26. 
Superior  articular  process.-. 


Demi-facet  for  head  of  rib. 


Facet  for  tubercle  of  rib. 


Demi-facet  for  head  of  rib. 


Inferior  aHicular  process. 


A  Dorsal  Vertebra, 
Fig.  2. — To  face  page  27. 


Superior  articular  process. 


Lumbar  Vertebra. 


THE  VERTEBRAL   COLUMN.  25 

atlas  are  oval  and  converge  in  front.  The^^  look  up  and  in,  and  form  a 
cup  for  the  occipital  cond.yles.  They  may  be  partially  subdivided  by  a 
transverse  groove,  and  below  the  inner  margin  of  each  is  a  tubercle  for 
the  transverse  ligament.  The  inferior  articular  surfaces  are  slightly  con- 
vex, nearly  circular,  and  do  not  wholly  cover  or  fit  the  superior  processes 
of  the  axis.  The  posterior  arch  presents  in  the  median  line  either  a 
ridge,  hollow,  or  small  tubercle.  If  a  spinous  process  were  well  developed 
here,  nodding  of  the  head  would  be  prevented.  Just  behind  the  lateral 
mass  is  a  smooth  sinus,  the  vertebral  notch.  The  transverse  processes 
are  not  bifid — are  large  and  strong  for  attachment  of  rotatory  muscles. 

Varieties, — The  posterior  or  anterior  bony  arch  may  be  incomplete ;  the  an- 
terior root  of  the  transverse  process  may  be  ligamentous.  A  spicule  of  bone 
may  bridge  over  the  superior  vertebral  notch,  and  the  canal  formed  be  sub- 
divided by  other  spicules.  The  artery  and  vein  go  through  the  upper  subdi- 
vision, the  suboccipital  nerve  through  the  lower. 

Describe  the  axis. 

The  second  vertebra,  vertebra  dentata  or  epistropheus  (to  "turn 
round  "),  forms  an  axis  upon  which  the  atlas  carrying  the  head  rotates. 
The  body  of  the  atlas  is  joined  upon  that  of  the  axis  in  form  of  a  tooth- 
like process,  the  odontoid.  Its  apex  is  pointed,  and  just  below  is  an  en- 
largement or  head,  both  giving  attachment  to  bands  of  the  check  liga- 
ment. 

The  process  has  in  front  a  smooth  articular  surface  for  the  arch  of  the 
atlas,  and  behind  a  smooth  groove  for  the  transverse  ligament.  This 
makes  a  slight  constriction,  but  hardly  a  neck. 

The  anterior  surface  of  the  body  presents  a  slight  ridge  separating  two 
depressions.  The  superior  articular  surface  lies  close  to  the  odontoid, 
upon  the  body  in  part  and  upon  the  pedicles ;  they  look  up  and  out. 
The  inferior  articular  surfaces  are  behind  the  upper,  and  resemble  corre- 
sponding ones  in  the  cervical  region.  The  spinous  process  is  grooved 
inferiorly — is  very  large  and  bifid,  in  contradistinction  to  that  of  the 
atlas.  The  transverse  processes  are  short,  with  the  anterior  tubercle 
nearly  suppressed.  The  inferior  vertebral  notch  is  in  front  of  the  artic- 
ular surface,  which  is  the  rule  for  both  notches  below  this  in  the  column. 

Describe  the  seventh  cervical  vertebra. 

This  has  a  long  spinous  process,  non-bifurcated,  tending  to  slope  down, 
and  projecting  under  the  skin  ;  hence  the  name  vertebra  prominens.  The 
transverse  processes  are  massive,  slightly  grooved,  with  a  small  foramen 
or  none  at  all ;  the  posterior  tubercle  is  large  and.  the  anterior  one  very 
small.  The  vertebral  artery  and  vein  do  not  pass  through  these  for- 
amina :  both  veins  may,  sometimes  the  left  artery  does ;  the  vessels  may 
enter  no  foramina  till  the  fourth  vertebra  is  reached. 

Varieties. — The  spine  of  the  sixth  vertebra  is  not  usually  bifid  ;  in  the  negro 
this  is  the  rule  also  for  the  third,  fourth,  and  fifth.  Bifurcation  of  spines  is 
peculiar  to  the  human  skeleton.    The  anterior  tubercle  of  the  sixth  is  large, 


26  BONES   OF   THE   TRUNK. 

and  called  Chassaignac^s  and  carotid  tubercle.  The  common  carotid  artery  may 
be  compressed  against  it :  opposite  this  level  the  omo-hyoid  crosses  beneath 
the  sterno-mastoid  muscle ;  the  inferior  thyroid  artery  crosses  beneath  the 
common  carotid  ;  the  cricoid  cartilage  is  opposite,  also  the  beginning  of  the  tra- 
chea and  oesophagus,  the  end  of  the  larynx  and  pharynx. 

All  known  mammals  have  seven  cervical  vertebrae,  except  the  sloth  and 
manatee,  which  have  six.  There  are  two  exceptions  recorded  in  man.  The 
number  bears  no  relation  to  length  of  neck ;  that  of  the  whale  and  giraffe  each 
contains  seven. 

Describe  the  dorsal  or  thoracic  vertebrae. 

The  body  is  relatively  small,  and  heart-shaped ;  its  antero-posterior 
and  transverse  diameters  are  nearly  equal,  and  its  depth  is  greater  behind 
than  in  front.  Where  the  arch  joins  the  body  there  are  articular  sur- 
faces for  the  heads  of  ribs,  generally  two  on  each  side,  one  at  the  upper 
and  one  at  the  lower  border.  Between  the  neck  of  a  rib  and  transverse 
process  is  the  costo-transverse  foramen.  In  the  cervical  region  this  is 
represented  by  the  vertebral  foramen,  and  in  the  lumbar  region  the  space 
is  filled  by  the  bony  mass  of  the  transverse  process.  The  cross-section 
of  a  dorsal  body  shows  a  slight  median  projection  for  purposes  of  strength, 
similar  to  the  linea  aspera  of  the  femur.  The  laminae  are  broad  and  flat 
and  overlap  each  other. 

The  superior  vertebral  notches  are  shallow  or  absent ;  the  inferior  are 
deep. 

The  spinous  processes  are  bayonet-shaped,  and  terminate  in  a  slight 
tubercle.  They  are  longest  and  most  oblique  from  the  fifth  to  the 
eighth. 

The  transverse  processes  are  directed  out  and  back,  and  terminate  in 
a  clubbed  extremity,  which  presents  an  articular  surface  for  the  tuber- 
osity of  a  rib,  and  also  two  indistinct'  tubercles,  one  from  the  upper  and 
one  from  the  lower  border.  The  articular  processes  are  nearly  vertical, 
with  their  smooth  surfaces  (superior)  looking  back  and  out,  the  inferior 
in  a  reverse  direction. 

The  spinal  foramen  is  nearly  circular,  and  smaller  than  in  other 
regions. 

What  dorsal  vertebrae  present  peculiar  characters? 

The  first,  tenth,  eleventh,  and  twelfth  are  to  be  distinguished.  The 
Jirst  dorsal  resembles  the  seventh  cervical.  Its  body  above  is  trans- 
versely concave  and  lipped.  The  superior  vertebral  notches  are  deep, 
the  superior  articular  processes  are  oblique,  and  the  spinous  process  is 
nearly  horizontal.  On  the  side  of  the  body,  close  to  the  upper  border, 
is  a  whole  facet  for  the  first  rib,  and  a  very  small  demi-facet  below  for 
the  second  rib. 

The  twelve  ribs  correspond  to  twelve  joint  surfaces,  but  these  are  di- 
vided, so  that  only  the  first,  eleventh,  and  twelfth  present  single  facets ; 
the  first  in  addition  has  a  half-facet,  and  the  tenth  has  one  demi-facet. 


THE   VERTEBRAL   COLUMN.  27 

The  upper  demi-facets  become  larger  on  succeeding  vertebrae,  and 
when  the  eleventh  is  reached  it  is  a  complete  facet. 

The  tenth  dorsal  touches  only  one  rib  on  a  side,  and  has  a  nearly  com- 
plete facet,  mostly  on  the  pedicle  at  its  upper  border.  The  transverse 
process  has  a  small  facet. 

The  eleventh  dorsal  has  one  complete  facet  on  each  side,  but  none  on 
the  transverse  process. 

The  twelfth  dorsal  has  a  single  facet  on  each  side. 

The  inferior  articular  surfaces  turn  out,  resembling  the  lumbar  verte- 
brae.    The  spinous  process  is  short  and  nearly  horizontal. 

The  transverse  processes  are  short,  and  present  near  their  extremities 
the  external^  superior^  and  inferior  tubercles^  which  correspond  respect- 
ively to  the  transverse^  inammillary^  and  accessory  processes  of  the  lum- 
bar vertebrae.  Rudiments  of  these  tubercles  may  be  seen  on  the  tenth 
and  eleventh  vertebrae.  The  row  of  costal  facets  forms  the  anterior  bor- 
der of  the  intervertebral  foramina.  The  ribs  in  moving  intrude  some- 
what upon  the  vessels  and  nerves  in  those  foramina;  hence  the  "float- 
ing," most  movable,  ribs  articulate  with  single  vertebrae. 

The  ninth  dorsal  may  be  lacking  in  the  lower  demi-facet;  the  eleventh 
may  take  the  lumbar  type  of  articular  process. 

Describe  the  lumbar  vertebrse. 

These  are  the  largest  of  the  movable  vertebrae.  They  have  no  costal 
articular  surfaces,  and  no  foramina  through  the  transverse  processes. 
The  body  is  reniform  in  outline,  broad  transversely,  and  deeper  in  front 
than  behind.  The  laminae  are  short  and  thick,  the  superior  notches 
shallow,  the  spinous  process  horizontal,  and  broad  and  thickened  at  its 
extremity. 

The  transverse  processes  are  slender  and  project  directly  out ;  they  are 
in  front  of  the  articular  processes,  and  are  considered  to  be  homologous 
with  the  ribs.  Their  extremities  lie  in  series  with  the  external  tubercles 
of  the  lower  dorsal  transverse  processes.  The  accessory  process  (anapoph- 
ysis)  lies  behind  each  lumbar  transverse  process  at  its  base,  and  points 
down.     It  is  large  in  some  animals,  and  locks  the  vertebrae  together. 

The  articular  surfaces  are  vertical,  the  superior  concave  looking  back 
and  in :  the  superior  are  farther  apart  than  the  inferior,  and  embrace  an 
inferior  pair  above  them. 

The  manimillary  process  [metapophysis)  projects  back  from  each  su- 
perior articular  process.  The  spinal  foramen  is  triangular,  larger  than 
in  the  dorsal,  and  smaller  than  in  the  cervical  regions. 

The  fifth  lumbar  is  massive,  the  inferior  articular  processes  wider  apart 
than  the  upper ;  the  transverse  processes  are  broad  and  conical,  and  the 
laminae  project  into  the  spinal  foramen. 

In  the  European  the  bodies  of  the  lumbar  vertebrae  are  collectively  deeper 
in  front  than  behind,  but  the  individual  segments  vary.  In  the  negro  the 
depth  of  the  five  bodies  is  greater  behind  than  in  front. 


28  fiONES   Ot^   THE   TRUNIC. 

FALSE  VERTEBRA. 
Describe  the  sacral  vertebrae. 

These  in  the  adult  form  the  os  sacrum:  it  is  placed  between  the  two 
hip-bones,  and  with  the  coccyx  completes  the  pelvic  wall  above  and 
behind.  The  bone  may  be  likened  to  a  shovel  in  shape,  and  is  wedge- 
shaped  in  four  directions:  (1)  is  narrower  from  side  to  side  at  its  apex 
than  at  its  base ;  (2)  is  thinner  antero-posteriorly  at  its  apex  than  at  its 
base  ;  (3)  the  dorsal  surface  is  narrower  than  the  anterior ;  (4)  a  projec- 
tion into  the  articular  surface  of  the  ilium  (Fig.  12).  The  bone  presents 
anterior,  posterior,  and  two  lateral  surfaces,  a  base,  an  apex,  and  a  central 
canal  for  description. 

The  ventral  smface  looks  considerably  downward,  forming  a  projec- 
tion with  the  last  lumbar,  the  sacro-vertehral  angle  of  about  1 20°.  this 
surface  is  concave  from  above  down  and  from  side  to  side,  and  is  crossed 
by  four  horizontal  ridges,  indicating  the  union  of  five  vertebrae.  At  the 
ends  of  the  ridges  are  four  anterior  sacral  foramina^  which  lead  ex- 
ternally into  grooves  on  the  lateral  masses. 

The  two  rows  of  foramina  are  vertical  and  parallel,  not  approaching 
below,  as  the  width  of  the  bodies  are  all  equal. 

The  dorsal  surface  looks  up  and  back,  is  convex  and  rough,  and  along 
the  median  line  are  three  or  four  small  spinous  processes,  more  or  less 
connected,  forming  a  ridge.  Below  the  ridge  is  a  triangular  opening, 
bounded  by  the  imperfect  laminae  of  the  fourth  and  fifth  sacral,  and  by 
the  inferior  articular  processes  of  the  last  sacral,  which  are  prolonged 
down  into  sacral  cornua,  meeting  corresponding  ones  from  the  coccyx. 
On  each  side  of  the  median  ridge  the  united  laminae  are  hollowed  into 
the  sacral  groove,  a  continuation  of  the  vertebral  groove  above  ;  next  ex- 
ternally is  a  row  of  tubercles  representing  articular  and  mammillary  pro- 
cesses ;  next  the  four  posterior  sacral  foramina,  opposite  to,  but  smaller 
than,  the  anterior.  They  correspond  to  the  spaces  between  two  transverse 
processes — the  anterior  to  the  spaces  between  two  ribs. 

The  lateral  mass  is  that  part  external  to  the  foramina,  broad  above 
and  narrow  below.  It  is  made  up  of  broadened  transverse  processes, 
rudiments  of  which  are  seen  outside  the  posterior  sacral  foramina :  the 
first  pair  are  large ;  the  second  are  smaller  and  enter  into  the  formation 
of  the  sacro-iliac  joint ;  the  third,  fourth,  and  fifth  give  attachment  to 
ligaments.  Anteriorly  are  four  shallow  grooves,  separated  by  ridges, 
which  give  attachment  to  slips  of  the  pyriformis.  Above  and  externally 
the  lateral  mass  shows  an  uneven  auricular  surface  with  its  convexity 
forward ;  it  articulates  with  the  ilium.  Behind  this  the  bone  is  still  more 
rough  for  attachment  of  the  posterior  sacro-iliac  ligament.  The  auric- 
ular surface  rests  on  two  and  a  half  vertebrae,  the  larger  part  belonging 
to  the  first ;  the  upper  three  are  therefore  called  the  true  sacral  vertebrae, 
and  the  other  two  the  caudal.  Lower  down  the  bone  terminates  in  the 
inferior  lateral  angle,  below  which  is  a  half-notch,  forming  a  foramen 
with  the  coccyx  for  the  fifth  sacral  nerve. 


FALSE   VERTEBRA.  29 

The  base  shows  the  reniform  first  sacral  body,  behind  which  is  the 
triangular  aperture  of  the  sacral  canal ;  on  each  side  of  this  is  a  large  ar- 
ticular process  bearing  a  large  mammillary  process.  In  front  of  this  is 
a  vertebral  groove  which  helps  form  the  last  lumbar  intervertebral  fora- 
men. Externally  is  a  modified  transverse  process,  and  in  front  of  that 
a  smooth  triangular  surface  continuous  with  the  iliac  fossa,  the  ala  of 
the  sacrum. 

The  apex  is  the  body  of  the  fifth  sacral  vertebra,  transversely  oval ; 
it  articulates  with  the  coccyx.  The  sacral  canal  curves  with  the  bone, 
and  becomes  smaller  as  it  descends.  A  transverse  section  is  triangular 
above,  but  flattened  and  then  semicircular  below.  From  it  there  pass 
out  four  pairs  of  intervertebral  foramina,  opening  anteriorly  and  pos- 
teriorly into  the  anterior  and  posterior  sacral  foramina,  and  closed  ex- 
ternally by  the  lateral  masses. 

The  human  sacrum  is  characterized  by  its  great  breadth  compared  to  the 

length.     The  sacral  index  I :j — I   in  the   male   European  is  112, 

negro  106,  gorilla  72.    The  sacrum  may  consist  of  six  pieces,  or  rarely  of  four. 
The  bodies  of  the  first  and  second  may  not  be  united,  forming  a  second 
J  "  promontory  "  at  this  point.     The  sacral  canal  may  be  open  more  than  usual 
or  open  throughout. 

What  are  the  differences  in  the  sacrum  of  the  male  and  female  ? 
In  the  female  it  is  wider,  sacral  index  116,  is  less  curved,  the  upper 
half  nearly  straight,  is  more  oblique,  and  forms  a  more  marked  prom- 
ontory than  in  the  male. 

Describe  the  coccygeal  vertebrae. 

These  are  very  rudimentary,  usually  four  in  number,  often  five, 
rarely  three.  Of  the  first  one  the  pedicles  and  superior  articular  cornua 
project  upward,  and  help  form  the  last  intervertebral  foramen.  The 
short  transverse  process  usually  bounds  a  notch  for  the  anterior  division 
of  the  fifth  sacral  nerve,  or  if  it  touches  the  inferior  lateral  angle  of  the 
sacrum,  it  forms  a  fifth  anterior  sacral  foramen. 

The  second  vertebra  has  rudiments  of  transverse  processes,  and  two 
small  eminences  in  line  with  the  cornua,  representing  the  last  traces  of 
a  neural  arch.  The  third  and  fourth  are  mere  nodules,  and  represent  ver- 
tebral bodies  only.  In  adult  life  the  first  piece  is  usually  separate,  and 
the  other  three  united.  All  four  may  form  one  bone,  which  occurs 
oftener  and  earlier  in  the  male. 

Steinbach  observes  that  the  male  has  most  often  five  coccygeal  vertebrae, 
and  the  female  four  or  five  with  equal  frequency. 

Describe  the  vertebral  column  as  a  whole. 

It  is  a  central  axis  upon  which  other  parts  are  arranged :  above,  it 
supports  the  head,  laterally  the  ribs,  and  it  rests  on  the  hip-bones  below. 
Its  average  length  measured  along  the  curves  is  28  inches  in  the  male, 


30  BONES   OF   THE   TRUNK. 

and  27  inches  in  the  female ;  persons  seated  in  a  row  appear  of  about 
the  same  height. 

Viewed  from  the  front,  the  column  is  formed  of  two  pyramids  applied 
base  to  base  at  the  junction  of  the  last  lumbar  with  the  sacrum.  The 
upper  pyramid  can  be  divided  into  three — viz.  the  six  lower  cervical,  with 
base  at  first  dorsal ;  the  second  is  inverted,  with  the  apex  at  fourth  dor- 
sal ;  and  the  third  commences  at  the  fourth  dorsal  and  ends  at  the  last 
lumbar.  All  three  diameters  of  the  vertebrae  increase  from  the  third 
cervical  to  the  last  lumbar :  vertical  diameter  from  f-lj  inches  (14  mm. 
to  29  mm.),  sagittal  from  f-lf  inches  (14  mm.  to  35  mm.),  transverse 
(does  not  increase  in  dorsal  region)  from  |-2J  inches  (21  mm.  to  55  mm. ). 

The  column  presents  a  lateral  curve  convex  to  the  right :  this  may  be 
an  indentation  on  the  left  side  rather  than  a  curve.  Three  theories  are 
proposed:  (1)  liver  draws  right  side  over;  (2)  pulsating  aorta  pushes 
column  over ;  (3)  right-handedness.  The  last  is  most  tenable.  V  iewed 
laterally,  there  are  four  curves,  alternately  convex  and  concave,  the 
cervical,  dorsal,  lumbar,  and  pelvic;  the  first  extends  from  the  odon- 
toid to  the  second  dorsal;  the  dorsal  curve  is  concave  forward  and 
ends  at  the  twelfth  dorsal;  the  lumbar  ends  at  the  sacro- vertebral 
angle,  and  the  pelvic  ends  at  the  tip  of  the  coccyx.  The  dorsal  and 
pelvic  curves  are  primary,  exist  at  birth,  enter  into  the  formation  of* 
bone-walled  cavities,  and  are  due  to  the  conformation  of  the  'vertebral 
bodies.  The  dorsal  is  produced  by  pressure  of  viscera  and  weight  of 
head  and  thorax.  ^  • 

When  the  child  begins  to  walk  the  ilio- psoas  muscles  pull  the  lumbar 
vertebrae  forward,  producing  here  and  in  the  cervical  region  secondary  or 
compensatory  curves,  mainly  due  to  the  shape  of  the  intervertebral  disks.* 
Sitting  and  the  weight  of  the  head  also  induce  the  cervical  curve. 

The  pathological  curvatures  are  called  7a/phosis  (humpbacked),  scolio- 
sis (crooked,  bent  to  one  side),  and  lordosis^  (bent  forward). 

Posteriorly,  the  spines  occupy  the  median  line  or  may  be  normally 
twisted  a  little  from  it.  In  the  cervical  region  they  are  short,  horizontal, 
and  bifid ;  in  the  dorsal  they  are  oblique  above,  vertical  in  the  mid  por- 
tion, and  horizontal  below ;  in  the  lumbar  they  are  horizontal.  A  cross- 
section  of  a  cervical  spine  is  semilunar ;  of  a  dorsal,  triangular ;  of  a 
lumbar,  oblong.  On  either  side  of  the  spines  is  the  vertebral  groove, 
bounded  externally  in  the  cervical  and  dorsal  region  by  the  transverse 
processes,  and  in  the  lumbar  by  the  mammillary  processes.  The  trans- 
verse processes  of  the  atlas  are  long ;  of  the  axis,  short,  increasing  to  the 
first  dorsal,  thence  diminishing  to  the  last  dorsal,  and  beconiing  suddenly 
much  longer  in  the  lumbar  vertebrae.  In  the  cervical  region  the  trans- 
verse processes  are  in  front  of  articular  processes  and  between  interver- 
tebral foramina.  In  the  dorsal  region  they  are  behind  both.  In  the 
lumbar  region  they  are  in  front  of  the  articular  processes  and  behind  the 
intervertebral  foramina. 

Intervertebral  foramina  are  always  in  front  of  articular  processes,  ex- 
cept those  of  the  atlas  and  the  upper  ones  of  the  axis.     They  are  named 


THE  THORAX.  31 

from  the  upper  of  the  two  vertebrae  which  go  to  form  them,  excepting 
in  the  cervical  region,  where  there  are  eight,  the  fissure  between  the 
skull  and  atlas  being  called  the  first. 

In  the  cervical  region  the  superior  articular  surfaces  look  back  and  up. 

In  the  dorsal  region  the  superior  articular  surfaces  look  back  and  out. 

In  the  lumbar  region  the  superior  articular  surfaces  look  back  and  in. 
The  inferior  surfaces  have  an  opposite  direction. 

The  spinal  canal  has  three  sets  of  openings  into  it,  the  two  rows  of 
the  intervertebral  foramina  and  the  intervertebral  fissures  between  the 
laminae.  It  is  naiTowest  in  those  parts  having  least  motion — viz.  in  the 
dorsal  and  sacral  regions.  It  is  round  and  f  inch  (17  mm.)  in  diameter 
in  the  dorsal  region  ;  is  triangular  with  apex  behind  in  the  cervical  and 
lumbar  regions ;  and  largest  of  all  in  the  cervical. 

OSSIFICATION   OP  THE  VERTEBRA. 

Each  vertebra  is  developed  from  three  primary  centres — one  on  each  side  for 
the  lamina  and  processes,  appearing  at  the  sikth  week  of  foetal  life,  and  one  for 
the  body  at  the  eighth  week.  Five  secondary  centres  are  added — three  for  the 
tips  of  the  spinous  and  transverse  processes,  and  two  for  thin  annular  plates  on 
the  circumferences  of  the  upper  and  lower  surfaces  of  the  bodies.  These  are 
not  united  till  the  twenty-fifth  year.  A  lumbar  vertebra  has  two  others  for 
the  mammillary  processes. 

The  atlas  has  three  primary  centres,  the  axis,  six ;  there  are  two  lateral 
ones  for  the  odontoid,  between  which  a  bit  of  cartilage  remains  till  advanced 
life ;  the  apex  of  the  odontoid  has  a  separate  centre.  The  seventh  cervical 
usually  has  a  separate  centre  in  the  anterior  part  of  its  transverse  process, 
and  likewise  the  first  lumbar,  though  infrequently.  The  ossification  of  the 
laminae  proceeds  from  above  down,  explaining  the  occurrence  of  spina  bifida 
in  the  lower  part  of  the  column  :  ossification  of  the  bodies  appears  first  in  the 
last  dorsal  and  extends  in  both  directions. 

The  sacrum  as  a  whole  is  developed  from  thirty-five  centres — fifteen  for  bodies 
and  arches,  ten  for  epiphysial  plates,  three  for  the  upper  part  of  each  lateral 
mass,  and  two  for  an  auricular  surface  and  thin  edge  below.  The  coccyx  has 
four  centres — one  for  each  piece,  sometimes  two  for  the  first  one. 

THE  THORAX. 

The  skeleton  of  the  thorax  comprises  the  dorsal  vertebrae,  the  ster- 
num, ribs,  and  costal  cartilages. 

Describe  the  sternum. 

The  breast-bone  is  an  azygos  bone  in  the  median  Hne  at  the  front  of 
the  chest.  It  has  attached  the  clavicles  and  seven  upper  costal  carti- 
lages. It  originally  consisted  of  six  segments,  and  is  likened  to  a  sword. 
The  upper  segment  remains  distinct  as  the  manubrium  or  handle;  the 
next  four  fuse  into  the  bo^y  or  gladiolus  (little  sword) ;  the  sixth  por- 
tion is  the  ensiform  or  xiphoid  jwocess  (sword-like). 

The  sternum  is  flattened  from  before  backward,  and  curved  with  a 
slight  convexity,  to  the  front.  It  is  broad  above,  then  narrow  to  the 
beginning  of  the  gladiolus,  then  broad  again,  and  narrow  at  the  ensi- 


32  BONES   OF   THE   TRUNK. 

form.  The  bone  contains  red  marrow,  confined  in  cancellous  tissue  be- 
tween two  thin  layers  of  compact  bone.  The  manubrium  (presternum) 
is  the  thickest  part,  concavo-convex  on  cross-section.  Superiorly  are 
three  deep  notches :  the  middle  one  is  the  semilunar  or  interclavicular 
notch ;  the  lateral  ones  look  up  back  and  out  for  articulation  with  the 
clavicles.  Below  the  lateral  notches  on  either  side  is  a  rough  triangular 
surface  for  union  with  the  first  costal  cartilage  ;  next  is  a  sloping  concave 
surface ;  and  at  the  lower  angle  a  half  notch  for  the  second  rib.  The 
junction  of  the  manubrium  with  the  gladiolus  is  always  prominent,  and 
serves  as  a  landmark  for  the  second  rib. 

The  body  (mesosternum)  is  marked  anteriorly  by  three  slight  trans- 
verse ridges.  Each  lateral  margin  presents  four  notches  and  two  half- 
notches  :  they  approach  each  other  from  above  down.  The  half-notch 
above  is  for  the  second  cartilage ;  the  notches^  for  the  third,  fourth,  and 
fifth  cartilages  are  opposite  the  lines  of  junction  of  the  four  segments ; 
the  notch  for  the  sixth  cartilage  and  the  half-notch  for  the  seventh  be- 
long to  the  inferior  segment.  "So  most  of  the  cartilages  of  the  true  ribs 
articulate  in  front  at  junctions  of  segments,  analogous  to  the  connection 
of  ribs  with  the  vertebral  column. 

The  ensiform 'process  (metasternum)  projects  down  between  the  carti- 
lages of  the  seventh  rib.  It  has  various  forms — may  be  bent  forward, 
backward,  or  laterally,  be  forked  or  perforated,  and  is  more  or  less  carti- 
laginous. At  its  upper  angle  is  a  half-notch  for  the  seventh  cartilage. 
The  sternum  is  subcutaneous  in  the  median  line,  forming  the  floor  of  the 
sternal  groove^  with  the  supra-  or  episternal  notch  above  and  the  iiifra- 
sternal  depression  at  the  ensiform  process. 

The  body  of  the  male  sternum  is  more  than  twice  as  long  as  the  manu- 
brium; in  the  female  it  is  less  than  twice  the  same  length.  The  body  at  the 
junction  of  the  third  and  fourth  segments  may  be  perforated  by  a  sternal 
foramen,  or  rarely  by  a  sternal  fissure.  Two  small  nodules,  ossa  suprasternalia, 
are  sometimes  found  close  inside  the  clavicular  notches:  they  represent  an 
episternal  bone  of  lower  animals,  other  remains  of  which  are  the  interartic- 
ular  fibro-cartilage  of  the  sterno-clavicular  joint.  In  flying  birds  a  great  keel 
exists  along  the  middle  of  the  sternum.  In  the  male  wild  swan  and  guinea- 
fowl  the  sternum  is  tunnelled  and  contains  the  trachea. 

Describe  the  general  characters  of  the  ribs. 

The  ribs  (costae)  are  twelve  in  number  on  each  side.  The  first  seven 
pairs,  attached  by  costal  cartilages  to  the  sternum,  are  called  sternal^ 
true,  or  vertebrosternal  ribs ;  the  remaining  five  pairs  are  asternal  or 
false  ribs :  each  of  the  upper  three  pairs  of  false  ribs  has  its  cartilage 
attached  to  the  cartilage  above  it,  vertebro-chondral ;  the  last  two  pairs 
have  no  such  attachment,  and  slyo  floating  o{  vertebral  ribs. 

Each  rib  presents  three  parts— a  body,  an  anterior  and  a  posterior 
extremity. 

The  posterior  extremity  is  thickened  into  the  head  or  capitulum :  it 
has  a  superior  and  an  inferior  articular  facet  for  articulation  with  two 


THE   THORAX.  33 

vertebrae ;  the  lower  is  the  larger,  and  between  them  is  a  ridge  for  the 
interarticular  cartilage. 

Next  externally  is  the  flattened  neck^  1  inch  long  (collum  costae),  and 
next  the  tuberosity^  divided  into  two  parts  by  an  oblique  groove.  The 
inner  and  lower  part  is  articular  for  the  transverse  process  of  the  lower 
of  the  two  vertebrae,  with  which  the  rib  is  connected ;  the  outer  and 
upper  part  is  rough  for  the  posterior  costotransverse  ligament. 

The  body  is  laterally  compressed,  and  over  its  most  convex  part  is  a 
rough  line  corresponding  to  the  outer  border  of  the  sacro-lumbalis  mus- 
cle, marking  the  angle;  still  farther  forward  is  another  line,  the  anterior 
angle.  The  inferior  border  presents  the  subcostal  groove,  best  marked 
at  the  angle  and  disappearing  in  front ;  it  lodges  intercostal  vessels  and 
nerves.  Starting  from  the  upper  and  inner  border  of  the  neck  is  a  su- 
perior costal  groove  soon  lost  on  the  body. 

The  anterior  extremity  is  hollowed  into  a  pit  for  union  with  the  costal 
cartilage.  The  ribs  are  curved  on  three  axes — a  vertical  one  near  the 
angle ;  also  a  transverse  one  at  this  place,  ^o  that  when  the  anterior  part 
of  the  rib  is  horizontal  the  posterior  will  rise  up  ;  and  a  longitudinal  one, 
so  that  the  anterior  part  looks  up  and  the  posterior  part  looks  down. 
The  upper  ribs  are  nearly  at  right  angles  with  the  spine,  and  reach  their 
greatest  obliquity  at  the  ninth.  The  seventh  or  eighth  rib  is  the  longest, 
after  which  they  decrease  to  the  twelfth.  The  first  is  broadest,  and  the 
twelfth  narrowest.  The  distance  from  the  angle  to  the  tuberosity  in- 
creases from  above  down. 

Describe  the  peculiar  ribs. 

The  first  rib  is  not  twisted,  and  its  surfaces  look  nearly  up  and  down. 
The  head  is  small  and  has  a  single  articular  facet :  the  neck  is  slender, 
and  the  angle  coincides  with  the  tuberosity.  ^  On  the  upper  surface  is  a 
rough  impression  for  the  scalenus  medius  muscle,  and  in  front  of  that  two 
smooth  depressions  with  an  intervening  ridge :  the  posterior  depression 
is  for  the  "third  portion  "  of  the  subclavian  artery,  the  ridge  ending  in 
the  scalene  tubercle  (Lisfranc's  tubercle)  is  for  the  attachment  of  the 
scalenus  anticus  muscle,  and  the  anterior  depression  for  the  subclavian 
vein.     There  is  no  subcostal  groove.  « 

The  second  rib  is  not  twisted  and  has  no  angle  (Henle) :  it  presents 
near  the  middle  depressions  for  the  scalenus  posticus  and  serratus  mag- 
nus  muscles.     It  has  a  double  articular  facet. 

The  eleventh  and  twelfth  ribs  have  single  articular  facets,  and  only 
slight  elevations  to  mark  the  tuberosities  which  do  not  articulate  with 
the  transverse  process- 

The  eleventh  has  a  slight  subcostal  groove ;  the  twelfth  has  no  angle. 

The  number  of  ribs  may  be  thirteen  on  one  or  both  sides ;  the  gorilla  and 
chimpanzee  have  each  thirteen  pairs  of  ribs.  The  added  rib  is  most  often 
connected  with  the  first  lumbar  transverse  process,  sometimes  with  the 
seventh  cervical  vertebra,  where  it  has  a  double  attachment— viz.  to  the  body 
and  to  the  transverse  process.  The  pleura  descends  to  the  same  spot  whether 
3— A. 


34  BONES   OF   THE   TRUNK. 

the  twelfth  rib  be  absent  or  not.     The  tenth  rib  may  have  but  one  articular 
facet.    The  twelfth  rib  varies  in  length  from  8  inches  to  less  than  1  inch. 

Describe  the  costal  cartilages. 

They  prolong  the  ribs  to  the  sternum.  Their  breadth  diminishes  from 
tlie  first  to  the  last ;  they  become  narrow  toward  their  sternal  extrem- 
ities ;  their  length  increases  to  the  seventh ;  the  first  descends  a  little, 
the  second  is  horizontal,  the  others,  except  the  last  two,  ascend  after 
following  the  direction  of  the  rib  for  a  short  distance.  Their  external 
extremities  are  convex,  and  planted  into  the  osseous  tissue  of  correspond- 
ing ribs.  The  inner  extremity  of  the  first  is  united  directly  to  the  sternum 
without  articular  cavity;  the  succeeding  six  have  rounded  extremities 
for  the  sternal  notches.  Each  cartilage  of  the  first  three  false  ribs  is 
united  to  the  lower  border  of  the  one  above  it.  The  fifth,  sixth,  seventh, 
and  eighth  cartilages  articulate  with  each  other ;  the  eleventh  and  twelfth 
are  pointed  and  unattached. 

The  eighth  may  articulate  with  the  sternum.  The  seventh  may  meet  its 
fellow  of  the  other  side  in  front  of  the  ensiform.  There  may  be  no  articula- 
tion between  the  fifth  and  sixth  ;  there  may  be  one  between  the  eighth  and 
ninth. 

Describe  the  thorax  as  a  whole. 

The  bony  thorax  is  conical,  and  flattened  from  before  backward.  The 
short  an tero- posterior  diameter  is  characteristic  of  man,  but  in  the  lower 
mammals  and  human  foetus  it  is  longer  than  the  transverse  diameter. 
The  posterior  wall  is  convex  forward,  and  a  broad  furrow  on  either  side, 
the  sulcus  pulmoncdis,  is  formed  by  the  ribs  as  they  project  backward,  so 
that  the  weight  of  the  body  is  more  equally  distributed  around  the 
column. 

The  anterior  wall  is  convex  and  at  an  angle  of  20°-25°  with  the  pos- 
terior. 

A  horizontal  antero-posterior  diameter  from  the  base  of  the  ensiform 
is  8  inches  (20  cm. ) ;  the  transverse  at  the  eighth  or  ninth  rib  is  11  inches 
(28  cm.) ;  the  vertical  anteriorly  is  6  inches  (15.5  cm.),  and  posteriorly 
iiPl2  inches  (31.5  cm.).  The  upper  border  of  the  sternum  is  opposite 
the  lower  edge  of  the  second  dorsal  (Henle),  and  the  lower  border  oppo- 
site the  tenth  dorsal.  The  sides  slope  out  to  the  ninth  rib.  The  upper 
aperture  is  contracted  and  reniform,  and  sloped  downward ;  the  lower  is 
irregular,  and  its  margin  ascends  on  each  side  from  the  tenth  rib  to  the 
ensiform,  forming  the  suhcostal  angle.  The  intercostal  spaces  are  wider 
above  than  below. 

The  sternum  is  developed  from  six  centres,  one  for  each  segment :  the  first 
to  appear  is  at  the  sixth  month  in  the  manubrium  ;  the  ensiform  centre  does 
not  appear  till  the  sixth  year.  The  manubrium  may  have  two  or  more 
centres,  and  the  third,  fourth,  and  fifth  segments  may  have  two  centres,  each 
placed  laterally :  if  the  bony  parts  formed  from  these  do  not  meet,  there  is 
left  the  sternal  foramen  or  fissure.     The  manubrium  and  body  exception- 


BONES   OF   THE    HEAD. 


35 


ally  join  by  bone,  and  usually  remain  separate  till  the  twenty-fifth  year. 
The  ensiform  unites  in  middle  life. 

A  single  centre,  situated  posteriorly,  appears  for  each  rib  at  the  eighth 
week  ;  after  puberty  two  secondary  centres  appeal-  in  the  cartilage  of  the  head 
and  tuberosity.     The  eleventh  and  twelfth  ribs  have  none  for  the  tuberosity. 

In  the  adult  the  first  costal  cartilage  usually  shows  superficial  ossification 
or  even  a  complete  bony  sheath.  In  advanced  life  the  other  cartilages  may 
be  covered  by  bone,  especially* anteriorly :  this  tendency  is  stronger  in  the 
male.    The  cartilage  itself  is  seldom  ossified. 

THE   HYOID   BONE. 

Describe  the  hyoid  bone. 

The  hyoid,  or  os  hnguae,  is  situated  at  the  base  of  the  tongue  opposite 
the  second  or  third  cervical  vertebra,  and  is  shaped  Uke  the  Greek  let- 
ter iipsilon.  Its  body  is  compressed  from  above  down  ;  the  anterior  sur- 
face looks  up  and  forward,  and  is  marked  by  a  crucial  ridge  with  a 
tubercle  in  the  centre  and  depressions  on  either  side  for  muscular  at- 
tachment. Its  posterior  surface  is  concave  and  faces  the  epiglottis. 
The  great  cormia  project  back  and  are  flat  from  above  down.  After 
middle  life  they  have  bony  union  with  the  bod3\  The  small  cornua  are 
short  and  conical,  and  project  up  and  back  from  the  junctions  of  the 
great  cornua  and  body ;  they  give  attachment  to  the  stylo-hyoid  liga- 
ments and  have  synovial  articulations  with  the  body.  There  are  five 
centres  of  ossification  for  the  five  parts. 


BONES  OP  THE  HEAD. 

The  skull  is  divided  into  two  parts,  the  cranium  amd/ace :  the  former 
protects  the  brain  ;  the  face  surrounds  the  mouth,  nasal  cavities,  and 
orbits  in  part. 

Face  has  fourteen  bones. 
(a)  unpairing : 

Vomer, 


Cranium  has  eight  bones. 
(a)  unpairing : 


ih)  pairing: 


Occipital, 
Sphenoid, 
Ethmoid, 
Frontal. 

Temporal, 

Parietal. 


{b)  pairing: 


Inferior  maxilla. 

Superior  maxilla, 

Palate, 

Lachiymal, 

Inferior  turbinate. 

Nasal, 

Malar. 


BONES  OF   THE   CRANIUM. 
Describe  the  occipital  bone. 

This  bone  (ob.  caput,  against  the  head)  is  flattened,  lozenge-shaped, 
and  bent  on  itself;  the  upper  anterior  surface  is  concave,  the  posterior 


36  BONES   OF   THE   HEAD. 

is  convex.  It  articulates  with  six  bones — two  parietal,  two  temporal,  the 
sphenoid  and  atlas. 

Below  and  in  front  the  bone  is  pierced  by  the  foramen  magnum  (for. 
occipitale)  for  the  passage  of  the  spinal  cord  and  membranes,  spinal  por- 
tions of  the  spinal  accessory  nerves,  and  two  vertebral  arteries  :  the  part 
behind  the  foramen  is  the  tabular  portion,  in  front  is  the  basilar  por- 
tion, at  the  sides  are  the  condylar  portions. 

The  superior  borders  with  the  parietals  form  the  lambdoid  suture  ;  the 
inferior  borders  from  the  lateral  angles  to  the  jugular  processes  articulate 
with  the  mastoid,  thence  with  the  petrous  portion  of  the  temporal;  the 
basilar  unites  with  the  sphenoid  by  cartilage  or  by  bone.  The  rhombic 
form  may  become  eight-sided  by  secondary  obtuse  angles  between  the 
upper  and  lateral,  the  lateral  and  lower  angles. 

The  tabular  portion  presents  posteriorly  near  the  centre  the  external 
occipital  protuberance,  from  which  the  superior  curved  line  arches  outward 
on  each  side  to  the  lateral  angles ;  a  little  above  this  may  usually  be  seen 
the  highest  or  supreme  curved  line.  Below  the  protuberance  is  a  median 
external  occipitcd  crest,  from  the  centre  of  which  passes  out  the  inferior 
curved  line  to  the  jugular  processes. 

To  the  supreme  curved  line  is  the  bony  attachment  of  the  epicranial  apo- 
neurosis ;  to  the  superior  curved  line,  most  internally,  the  biventer  cervicis, 
for  the  inner  third  the  trapezius,  next  the  occipitalis,  sterno-cleido-mastoid, 
and  splenius  capitis.  Between  the  superior  and  inferior  lines  are  internally  a 
large  impression  for  the  complexus,  and  externally  a  small  one  for  the  supe- 
rior oblique.  Below  the  lower  line  is  an  inner  impression  for  the  rect.  cap. 
post,  minor,  and  an  outer  one  for  the  major.  The  ligamentum  uuchse  is  at- 
tached to  the  protuberance  and  crest. 

The  deep  surface  of  the  tabular  portion  shows  two  ridges  crossing  each 
other,  one  from  the  upper  angle  to  the  foramen  magnum,  one  connect- 
ing the  two  lateral  angles.  Where  these  intersect  is  the  internal  occi- 
pital protuberance,  not  always  opposite  the  external.  The  ridges  mark 
oif  four  hollows,  the  superior  and  inferior  occipital  fossae,  which  lodge 
the  posterior  cerebral  and  the  cerebellar  lobes.  The  ridges  are  grooved 
for  venous  sinuses.  The  space  where  the  longitudinal  sinus  is  continued 
into  a  lateral  one,  generally  the  right,  lodges  the  torcidccr  Herophili 
(wine-press  of  Herophilus).  Below  this  the  vertical  ridge  is  sharp,  and 
named  the  internal  occipital  crest. 

The  condylar  jwrtions  bear  the  articular  surfaces  for  the  atlas  :  these 
condyles  converge  toward  the  front,  are  doubly  convex,  and  somewhat 
everted.  At  the  inner  side  of  each  is  a  rough  impression  for  a  lateral 
odontoid  ligament.  Perforating  the  condyle  from  within  out  is  the  an- 
terior condylar  foramen  for  the  hypoglossal  nerve  and  a  branch  of  the 
ascending  pharyngeal  artery.  Immediately  above  this  foramen  is  a  heap- 
ing up  of  bone  designated  as  the  eminentia  innominata.  Behind  the 
condyle  is  a  posterior  condylar  fossa :  it  may  be  perforated  by  a  foramen 
for  the  passage  of  a  vein  from  the  lateral  sinus ;  both  fossa  and  foramen 
are  inconstant.     External  to  the  condyle  is  the  jugular  process,  analogue 


BONES   OF   THE   CRANIUM.  37 

of  a  transverse  process :  it  lies  above  the  transverse  process  of  the  atlas, 
and  it  presents  in  front  the  jugular  notch^  which  helps  form  the  jugular 
foramen  ;  the  right  notch  is  usually  the  larger.  The  extremit}^  of  the 
process  presents  an  irregular  facet  for  union  with  the  temporal  bone  ;  this 
union  is  osseous  at  the  twenty-fifth  year.  The  upper  surface  presents  the 
end  of  the  lateral  sulcus  leading  to  the  jugular  notch  :  here  the  posterior 
condylar  foramen  opens  if  i)resent.  On  the  under  surface  is  attached 
the  rect.  cap.  lateralis  muscle. 

The  basilar  2yi'ocess  projects  forward  and  upward  in  the  middle  of  the 
base  of  the  skull  and  at  the  top  of  the  pharynx,  increasing  in  thickness 
and  diminishing  in  width.  Superiorly  is  a  basilar  groove  for  the  medulla, 
and  at  either  lateral  margin  a  shallow  sulcus  for  the  inferior  petrosal 
sinus.  Inferiorly  in  the  middle  line  is  the  2)]iaryngeal  tubercle  for 
aponeurotic  attachment  of  the  superior  constrictor  of  the  pharynx :  on 
each  side  of  it  are  attached  the  rect.  cap.  anticus  major  and  minor 
muscles. 

The  portion  of  bone  above  the  superior  curved  line  (intraparietal)  is  some- 
times separated  from  the  rest  by  a  transverse  suture.  The  bone  between  the 
supreme  and  superior  curved  lines  may  be  very  prominent  and  constitute  the 
torus  occipitalis  transversus  (transverse  bulge).  An  intrajugular  process  may 
project  into  the  jugular  notch.  From  the  under  aspect  of  the  jugular  process 
the  paramastoid  process  may  descend  to  the  transverse  process  of  the  atlas. 
There  is  a  rare  articulation  between  the  basilar  process  and  anterior  arch  of 
the  atlas  or  odontoid.  Birds  and  reptiles  have  only  a  single  occipital  condyle, 
placed  in  front  of  the  foramen  magnum.  The  external  occipital  crest  is 
greatly  developed  in  most  animals. 

Describe  the  parietal  bone. 

This  bone  is  quadrilateral,  convex  externally  and  concave  internally,  a 
little  broader  above  than  below.  It  articulates  with  five  bones — the 
opposite  parietal,  the  occipital,  frontal,  sphenoid,  and  temporal.  Near 
the  middle  of  the  outer  surface,  nearer  the  lower  than  upper  border,  is 
the  parietal  eminence  or  boss.     This  is  very  prominent  in  young  bones. 

Through  or  just  below  this  are  the  superior  and  inferior  temporal  lines, 
f  inch  apart:  to  the  superior  one  is  attached  the  temporal  fascia,  to  the 
inferior  the  temporal  muscle.  The  inferior  line  does  not  pass  off  the 
parietal  upon  the  occipital  bone ;  below  it  is  the  temporal  surface  for 
origin  of  the  temporal  muscle.  Near  the  upper  border,  and  f  inch  (20 
mm.)  from  the  posterior  angle,  is  the  parietal  foramen  for  the  exit  of 
a  vein,  and  usually  entrance  of  a  branch  of  the  occipital  artery.  The 
sagittal  suture  between  the  two  parietal  foramina  is  inclined  to  oblite- 
ration. 

The  deepest  part  of  the  inner  surface  opposite  the  parietal  eminence 
is  the  parietal  fossa.  The  inner  surface  is  marked  by  furrows  or  canals 
for  the  meningeal  vessels.  A  slight  depression  runs  along  the  superior 
border,  forming  part  of  the  sulcus  for  the  longitudinal  sinus.  At  the 
posterior  inferior  angle  is  a  groove  for  the  lateral  sinus,  which  first  runs 


38  BONES   OF   THE    HEAD. 

across  the  occipital,  then  this  angle  of  the  parietal,  then  the  mastoid  por- 
tion of  the  temporal,  and  finally  the  jugular  process  of  the  occipital. 
Near  the  upper  border  of  the  bone  are  digital  depressions  for  the  lodg- 
ment of  Pacchionian  bodies  (modified  tufts  of  arachnoid  membrane). 

The  anterior  border  is  alternately  bevelled,  so  that  the  frontal  rests 
upon  it  above  and  the  parietal  overlaps  the  frontal  below,  thus  resisting 
the  usual  directions  of  violence.  The  inferior  border  is  flattened  and 
squamous,  and  divided  into  three  parts,  named  from  the  bones  over- 
lapping it,  sphenoid,  squamous,  and  mastoid  from  before  backward. 

The  parietal  foramen  may  be  absent  on  one  or  both  sides  or  may  be  very 
large.    This  bone  is  bipartite  iu  some  Australian  skulls. 

Describe  the  frontal  bone. 

The  frontal  {frons,  forehead)  arches  up  and  back  above  the  orbits, 
forming  the  fore  part  of  the  cranium.  It  articulates  with  twelve  bones 
— the  parietals  and  sphenoid,  the  malars,  the  nasals,  superior  maxillse, 
lachrymals,  and  ethmoid.  Inferiorly  are  two  thin  horizontal  laminae, 
the  orbital  plates,  forming  the  roof  of  the  orbits  and  separated  by  tlie 
ethmoidal  notch.  Three  surfaces  are  presented  for  description.  The 
anterior  surface  shows  the  greatest  convexity  on  each  side  in  the  frontal 
eminence,  separated  by  a  slight  depression  below  from  the  superciliary 
ridge,  just  above  the  orbit.  In  the  middle  line  between  the  two  ridges 
is  a  smooth  surface,  the  glabella  (without  hair),  also  called  nasal  emi- 
nence. The  orbital  arch  ends  in  extremities  called  the  internal  and 
external  angular  processes :  the  internal  is  slightly  marked,  and  articu- 
lates with  the  lachrymal  bone ;  the  external  is  prominent,  and  articulates 
with  the  malar.  At  the  junction  of  the  inner  and  middle  third  of  the 
arch  is  the  supraorbital  notch  or  foramen  for  the  supraorbital  nerve  and 
vessels.  The  temporal  crest  springs  from  the  outer  angular  process,  and 
is  continuous  with  the  inferior  temporal  line  on  the  parietal. 

Inferior  Surface. — The  orbital  plates  are  somewhat  triangular,  with 
their  internal  margins  parallel.  Close  to  the  external  angular  process 
is  the  lachrymal  fossa,  and  close  to  the  inner  process  is  the  trochlear 
fossa  for  the  pulley  of  the  superior  oblique.  Between  the  internal  an- 
gular processes  is  the  nasal  notch,  and  from  its  concavity  the  nasal 
process  projects  beneath  the  nasal  bones  and  nasal  processes  of  the 
superior  maxillae  and  supports  the  bridge  of  the  nose.  On  the  posterior 
surface  of  this  process  are  two  grooves  which  enter  into  the  roof  of  the 
nasal  fossae ;  between  the  grooves  is  a  median  ridge,  the  nasal  spine, 
which  descends  in  the  septum  of  the  nose  above  the  perpendicular  plate 
of  the  ethmoid.  Along  the  inner  margins  of  the  ethmoidal  notch  are 
irregular  depressions  forming  the  roof  of  cells  in  the  ethmoid.  Each 
border  is  marked  inferiorly  by  two  grooves,  completing  with  the  ethmoid 
the  anterior  smd  posterior  internal  orbital  canals :  the  anterior  transmits 
the  nasal  nerve  from  the  orbit  and  anterior  ethmoidal  vessels  j  the  pos- 
terior transmits  the  posterior  ethmoidal  vessels.    The  frontal  sinus  opens 


BONES   OF   THE   CRANIUM.  39 

at  the  root  of  the  nasal  process.  It  is  between  the  outer  and  inner 
tables,  over  the  root  of  the  nose  and  divided  by  a  bony  septum.  Out- 
side and  behind  the  orbital  surface  is  a  rough  triangular  area  for  articu- 
lation with  the  great  wing  of  the  sphenoid. 

Cerebral  Surface. — This  forms  a  large  concavity  for  the  anterior  lobes 
of  the  cerebrum.  The  orbital  plates  are  convex  and  marked  by  ridges 
and  depressions,  and  are  so  thin  as  to  be  transparent :  these  plates  make 
an  angle  of  about  60°  with  the  upper  part  of  the  bone.  From  the  upper 
margin  descends  the  frontal  sulcus,  running  into  the  frontal  crest  at  the 
lower  margin.  At  the  base  of  the  crest  is  usually  a  groove  converted 
into  the  foramen  cwcvm  by  the  approximation  of  the  ethmoid ;  this  is 
usually  open  in  children,  but  blind  in  adults.  The  sides  of  this  surface 
present  grooves  for  the  meningeal  vessels.  The  thin  transverse  edge 
bounding  the  surface  behind  articulates  with  the  greater  and  lesser  wings 
of  the  sphenoid. 

The  trochlear  fossa  may  be  absent  or  have  in  addition  a  trochlear  spine. 
The  bone  may  be  divided  by  the  frontal  or  metopic  suture,  the  infantile 
halves  having  failed  to  unite :  this  occurs  in  8  per  cent,  of  European  skulls, 
5  per  cent,  of  Mongolian,  and  1  per  cent,  of  African.  A  trace  of  the  suture 
is  seen  in  nearly  all  adult  frontal  bones  just  above  the  nasal  notch. 

Describe  the  temporal  bone. 

The  temporal  bone  (tempus,  time,  as  hair  first  becomes  gray  in  this 
region,  indicating  age)  helps  form  the  side  and  base  of  the  skull  and  con- 
tains the  organ  of  hearing.  It  presents  four  parts — the  squamous,  mas- 
toid, and  pyramidal y  which  includes  the  petrous  and  tympanic.  It  ar- 
ticulates with  five  bones — posteriorly  and  internally  with  the  occipital, 
above  with  the  parietal,  in  front  with  the  sphenoid  and  malar,  and  below 
with  the  inferior  maxilla. 

The  squamous  portion  (scale),  or  squamo-zygomatic,  presents  a 
vertical  portion  and  a  narrow  horizontal  portion  at  the  base  of  the  skull. 
It  is  limited  above  by  an  arched  border  describing  two-thirds  of  a  circle. 
The  outer  surface  is  vertical,  with  a  slight  convexity,  and  forms  part  of 
the  temporal  fossa.  This  portion  overlaps  the  mastoid.  Above  the 
aperture  of  the  ear  is  a  vertical  groove  for  the  middle  temporal  artery. 

The  zygoma  is  connected  with  the  lower  and  outer  part  of  the  squa- 
mous portion  :  it  is  broad  at  its  base,  with  surfaces  looking  up  and  down ; 
it  then  twists  on  itself,  so  that  it  has  inner  and  outer  surfaces,  upper  and 
lower  borders.  The  upper  border  is  thin  and  longer  than  the  inferior, 
which  is  short  and  arched ;  the  anterior  extremity  articulates  with  the 
malar.  The  zygoma  is  attached  by  two  roots :  the  anterior,  continuous 
with  the  lower  border,  is  a  broad  convex  ridge  directed  inward,  called 
the  eminentia  articularis.  At  the  junction  of  this  with  the  zygoma  is  a 
tubercle  for  the  external  lateral  ligament  of  the  lower  jaw.  The  poste- 
rior root  prolongs  the  upper  border  of  the  zygoma  as  the  supramastoid 
crest,  which  becomes  continuous  with  the  lower  temporal  line ;  it  is  above 
the  suture  between  the  squama  and  mastoid.     Between  the  two  roots  is 


40  BONES   OF   THE   HEAD. 

the  glenoid  fossa :  its  articular  portion  is  bounded  behind  by  the  post- 
glenoid  process,  sometimes  called  the  middle  root  of  the  zj^goma.  It  is 
strongly  developed  in  some  mammals  to  prevent  posterior  dislocation  of 
the  lower  jaw.  The  inferior  aspect  of  the  horizontal  portion  presents 
three  districts — the  auricular,  articular,  and  zygomatic,  from  behind 
forward.  The  auricular  part  forms  the  upper  concave  margin  of  the 
external  auditory  meatus  and  a  part  of  the  roof  of  the  external  ear. 
The  next  portion  is  the  glenoid  fossa,  which  is  divided  into  two  parts  by 
the  transverse  fissure  of  Glaser.  The  posterior  part  is  non-articular, 
formed  by  the  tympanic  plate  and  lodging  part  of  the  parotid  gland. 
The  anterior  part  of  the  fossa  is.  articular,  bounded  behind  by  the  post- 
glenoid  process  and  in  front  by  the  eminentia  articularis ;  it  is  the  fossa 
mandibular i^,  concavo-convex  for  the  condyle  of  the  lower  jaw.  The 
fissure  of  Glaser  is  a  double  cleft.  The  first  fissure  behind  the  artic- 
ular fossa  is  the  petro-squamous  (fps,  Fig.  1),  next  comes  a  narrow  pro- 
jection of  the  tegmen  tympani  (tt^)  from  the  petrous,  and  next  the 
petro-tympanic  fissure  or  Glaserian  fissure  proper :  it  lodges  the  slender 
process  of  the  malleus  and  tympanic  branch  of  the  internal  maxillary 
artery.  Farther  in,  and  external  to  the  Eustachian  tube,  is  the  canal  of 
Huguier,  by  which  the  chorda  tympani  nerve  enters.  The  outer  part 
of  the  Grlaserian  fissure  is  entirely  closed. 

Sometimes  a  "  false  jugular  foramen  "  is  present  in  the  squamous,  by  which, 
in  the  embryo  and  many  animals,  blood  flows  from  the  cranium  to  the  exter- 
nal jugular  vein.  It  is  between  the  articular  fossa  and  external  auditory 
meatus. 

In  front  of  the  articular  eminence,  and  separated  by  a  slight  ridge 
from  the  temporal  surface,  is  a  small  triangular  infratemporal  surface, 
entering  into  the  zygomatic  fossa. 

The  inner  surface  of  the  squamous  is  concave  and  presents  cerebral 
impressions  and  meningeal  grooves.  A  narrow  horizontal  part  helps 
form  the  anterior  wall  of  the  tympanum.  y 

The  superior  border  is  thin  and  fluted,  and  overlaps  the  parietal  bone. 
The  parietal  notch  marks  the  junction  of  the  superior  border  with  the 
mastoid  :  the  squamo-mastoid  suture  passes  from  this  notch  to  the  poste- 
rior edge  of  the  external  auditory  meatus. 

The  antero-inferior  border  is  thick,  and  bevelled  above  continuously 
with  the  upper  border  at  the  expense  of  the  inner  surface,  below  at  the 
expense  of  the  outer — all  for  articulation  with  the  great  wing  of  the 
sphenoid. 

The  mastoid  portion  (teat-like)  is  rough  for  muscular  attachment, 
and  prolonged  down  behind  the  auditory  meatus  as  the  mastoid  process. 
At  the  posterior  border  is  the  mastoid  foramen,  sometimes  foramina,  trans- 
mitting veins  from  the  lateral  sinus  and  a  mastoid  artery  from  the  occip- 
ital :  the  foramen  is  inconstant,  and  may  be  in  the  occipital  bone  or  in 
the  masto-occipital  suture.  On  the  inner  side  of  the  mastoid  process  is 
the  digastric  fossa  for  attachment  of  the  posterior  belly  of  the  digastric, 


BONES  OF   THE   CRANIUM.  41 

and  internal  to  this  is  the  sulcus  occipitalis  for  lodgment  of  the  occipital 
artery. 

The  internal  surface  shows  the  fossa  sigmoidea,  which  is  a  part  of  the 
sulcus  for  the  lateral  sinus :  the  mastoid  foramen  opens  into  it.  A  sec- 
tion of  the  mastoid  portion  shows  a  number  of  communicating  cells ;  be- 
low in  the  mastoid  process  they  are  developed  after  puberty  and  are 
arranged  vertically.  Above  these  is  the  antrum  mastoideum,  which  is  a 
horizontal  cellular  cavity,  a  part  of  the  middle  ear :  its  roof  and  postero- 
lateral wall  is  formed  from  the  petrous  portion,  and  is  continuous  with 
the  roof  and  side  of  the  tympanum.  Its  antero-median  wall  belongs  to 
the  mastoid.  Below  it  connects  with  the  mastoid  cells :  its  opening  into 
the  tympanum  is  large  and  on  a  level  with  the  foramen  ovale,  so  the  floor  of 
the  tympanum  passes  in  front  into  the  Eustachian  tube  and  behind  into 
the  mastoid  antrum.  The  sujKrior  border  of  the  mastoid  is  rough,  slopes 
back,  and  articulates  with  the  postero-inferior  angle  of  the  parietal :  the 
posterior  border  articulates  with  the  occipital  between  its  lateral  angle 
and  jugular  process. 

The  pyramidal  portion  includes  the  petrous  (stone)  and  tympanic 
(drum).  The  petrous  portion  is  a  four-sided  pyramid  with  its  base  turned 
out,  and  its  long  axis  inward,  forward,  and  slightly  downward.  The 
axes  of  the  two  portions  if  prolonged  w^ould  meet  at  the  posterior  edge 
of  the  nasal  septum.  This  portion  presents  four  borders — superior, 
inferior  J   anterior,   and  posterior;    and  four  surfaces — antero-internal 

Ftg.  1. 


(lA,  Fig.  1),  postero-internal  (ip),  antero-external  (ea),  and  postero-ex- 
ternal  (ep)  ;  also  a  base  and  an  apex.  The  base  is  concealed  in  its 
upper  half  by  the  squamous  and  mastoid,  and  covered  below,  where  these 
diverge,  by  the  tj^mpanic  portion.  The  apex  is  received  into  the  angle 
between  the  great  wing  of  the  sphenoid  and  the  basilar  process,  and  pre- 


42  BONES   OF   THE   HEAD. 

sents  the  anterior  orifice  of  the  carotid  canal,  and  forms  the  postero-ex- 
ternal  boundary  of  the  foramen  lacerum. 

The  antero-interrial  surface  is  in  the  middle  fossa  of  the  skull,  and 
separated  from  the  squamous  portion  by  the  fissura  petro-squamosa 
(fps).  This  surface  presents  a  little  behind  its  centre  the  eminentia 
arciiata,  covering  the  superior  semicircular  canal ;  in  front  of  this  is  a 
groove  leading  to  the  hiatus  Fallopu,  which  leads  to  the  aqueduct  of 
Fallopius ;  it  transmits  the  large  superficial  petrosal  nerve  and  the  pe- 
trosal branch  of  the  middle  meningeal  artery.  Outside  this  is  a  groove 
and  small  foramen  for  the  small  superficial  petrosal  nerve.  Near  the 
apex  the  wall  of  the  carotid  canal  is  deficient ;  above  this  is  a  shallow 
depression  for  the  Gasserian  ganglion.  Between  the  petro-squamous 
fissure  externally  and  the  hiatus  Fallopii  and  eminence  of  the  superior 
semicircular  canal  internally  is  a  thin  lamina  which  roofs  in  the  tym- 
panum and  a  common  canal  for  the  Eustachian  tube  and  tensor  tympani 
muscle :  it  is  the  tegmeii  tympani^  tt^,  a  process  of  the  petrous. 

The  postero-internal  surface  is  in  the  posterior  fossa  of  the  skull,  and 
continuous  with  the  inner  surface  of  the  mastoid.     Near  the  centre,  but 

nearer  the  upper  than  the  lower  bor- 

FiG.  2.  der,  is  a  large  orifice,  the  porus  acust. 

mrRLL.         flft.cRiB.sup.  int.^  leading  into  a  canal  J  inch  (6  mm. ) 

\.-«!mZ  loi^oj   which   is  the  internal  auditory 

^^^^k  meatus ;  this  is  terminated  by  the  lam- 

tfff/sn? /wir//^-^^^^^^  2*?ia  crihrosa  (Fig.  2).      A  transverse 

poit.uMTcoc/fr^^^^m^^^  Tidgc,   cruta  jalcijormis^    separates  a 

^^^^    /W.5/-W.  small  superior    from  a  large  inferior 

TMCT.sFtR.Fo/ffrM.  fossa.     A  faiut  perpendicular  crest  di- 

vides these  into  four  fossae.  The  facial 
nerve  enters  the  aqueduct  of  Fallopius  in  the  upper  anterior  fossa ;  the 
area  crihrosa  superior  is  the  perforated  part  of  the  upper  posterior  fossa 
for  auditory  nerves  going  to  the  utricle,  superior,  and  external  auditory 
canals;  below  this  is  the  area  crihrosa  media,  conveying  an  auditory 
branch  to  the  saccule  ;  also  the  foramen  singulare  for  a  branch  to  the 
posterior  auditory  canal ;  in  the  lower  anterior  fossa  is  the  tractus  spiralis 
foraminulentus,  for  the  cochlear  division  of  the  auditory  nerve,,  ending 
at  the  foramen  centrale  cocJilece. 

Behind  the  auditory  meatus  is  a  small  slit,  the  opening  of  the  aque- 
duct of  the  vestihule,  transmitting  a  small  artery  and  vein  and  lodging  a 
process  of  dura  mater  which  encloses  the  saccus  endolymphaiicus ;  above 
and  between  these  is  a  depression  or  fissure,  the  suharcuate  fossa,  which 
extends  into  the  arch  of  the  superior  semicircular  canal  and  represerfts 
the  floccular  fossa  of  animals. 

The  postero-external  surface  forms  part  of  the  base  of  the  skull. 
Beginning  at  the  apex,  is  first  a  quadrilateral  surface  for  the  origin  of 
the  levator  palati  and  tensor  tympani  muscles,  the  lower  aperture  of  the 
carotid  canal,  which  is  first  vertical  and  then  horizontal ;  vertically  be- 


BONES   OF   THE    CRANIUM.  43 

neath  the  internal  auditory  meatus  is  the  three-sided  opening  of  the 
aqueduct  of  the  cochlea,  which  in  early  life  transmits  a  vein ;  next  be- 
hind is  the  jugular  fossa,  which  forms  the  jugular  foramen  when  oppo- 
site the  jugular  notch  of  the  occipital. 

In  front  of  the  bony  ridge,  between  the  carotid  canal  and  jugular 
fossa,  is  a  small  foramen  for  Jacohso7is  nerve  (from  the  glosso-pharyn- 
geal)  to  the  tympanic  plexus ;  this  foramen  usually  splits  to  give  exit  to 
the  small  deep  petrosal  [carotico-tympanicus  superior)  from  the  tym- 
panic to  the  carotid  plexus.  Externally  in  the  ascending  part  of  the 
carotid  canal  is  a  small  foramen  for  the  carotico-tympamcus  inferior,  a 
sympathetic  nerve  going  from  the  carotid  plexus  to  the  tympanic.  On 
the  outside  of  the  jugular  fossa  is  a  foraraen  for  Arnold's  nerve  from  the 
pneumogastric :  its  canal  runs  through  the  petrous  transversely  and  out, 
and  splits  into  two,  an  inner  to  meet  the  facial  canal,  ^  inch  (5  to  6  mm.) 
above  the  stylo-mastoid  foramen,  and  the  other  to  open  at  the  tympanico- 
mastoid  (auricular)  fissure. 

Behind  the  jugular  fossa  is  the  jugular  facet,  'for  articulation  by  syn- 
chondrosis with  the  jugular  process  of  the  occipital.  Externally  is  the 
styloid  process,  enclosed  between  the  layers  of  the  vaginal  process.  It 
gives  attachment  to  three  muscles  and  two  ligaments.  Between  the  sty- 
loid and  mastoid  processes  is  the  stylo-mastoid  foramen,  the  end  of  the 
aqueductus  Fallopii,  which  passes  first  out  and  back  over  the  labyrinth, 
then  in  and  back,  and  then  down  to  terminate  here :  the  stylo-mastoid 
artery  enters  this  foramen. 

The  antero-external  surface  is  free  anteriorly  for  a  short  distance,  and 
articulates  with  the  great  wing  of  the  sphenoid ;  posteriorly  it  is  con- 
cealed by  the  tympanic  plate  (pt.  Fig.  1). 

At  the  angle  between  the  squamous  and  petrous  portions  is  the  open- 
ing of  a  canal  the  musculo-tubarius  (cm),  incompletely  divided  into  two 
by  a  projecting  lamella,  the  cochleariform  process  or  septum  tuhce  (STU). 
The  upper  groove  is  for  the  tensor  tympani  muscle,  and  the  lower  is  the 
bony  wall  of  the  Eustachian  tube.  This  common  canal  is  covered  by 
the  tegmen,  its  inner  wall  is  the  antero-external  surface  of  the  petrous, 
and  its  floor  and  outer  wall  are  the  tympanic  plate.  The  septum  tubse 
rarely  reaches  the  opposite  wall,  and  rises  from  the  anterior  wall  of  the 
carot!id  canal  (cca).  This  wall  is  made  of  two  thin  lamellae  with  diploe 
between,  in  which  runs  the  small  deep  petrosal  nerve.  The  superior 
harder  is  grooved  for  the  superior  petrosal  sinus,  and  gives  attachment 
to  the  tentorium  cerebelli.  The  posterior  border  presents  on  its  inner 
portion  a  half  groove  for  the  inferior  petrosal  sinus,  and  externally  the 
margin  of  the  jugular  fossa.  From  the  apex,  where  a  bony  projection 
often  overhangs  the  inferior  petrosal  groove,  a  fibrous  band,  the  petro- 
sphenoidal  ligament,  extends  to  the  side  of  the  dorsum  sellae,  and  com- 
pletes a  foramen  for  the  inferior  petrosal  sinus  and  sixth  nerve.  The 
anterior  harder  has  two  parts — an  outer,  forming  the  petro-squamous 
fissure,  and  an  inner  free  portion  to  form  the  petro-sphenoidal  suture. 
The  inferior  harder  is  largely  concealed  by  the  tympanic  and  petrous 


44  BONES   OF  THE   HEAD. 

portions:  near  the  apex  it  is  indistinct,  and  here  the  bone  is  rather 
three-sided. 

The  tympanic  portion  is  beneath  the  petrous  and  between  the  mas- 
toid and  squamous.  At  birth  it  is  a  ring  from  which  is  developed  the  tym- 
panic plate.  The  thickened  outer  extremity  of  this  plate  is  the  external 
auditory  process^  a  curved,  uneven  lamina  forming  the  anterior  and  in- 
ferior wall  of  the  external  auditory  meatus  and  t^^mpanum.  The  upper 
margin  of  the  plate  is  concealed  by  the  petrous  and  forms  the  posterior 
boundary  of  the  fissure  of  Glaser.  Its  lower  margin  descends  as  a  sharp 
edge,  the  vaginal  process :  it  is  continuous  with  the  inferior  border  of 
the  petrous  portion. 

Describe  the  sphenoid. 

The  sphenoid  bone  (wedge-like)  is  placed  across  the  base  of  the  skull 
near  its  middle,  and  binds  the  other  cranial  bones  together.  It  helps 
form  the  cavities  of  the  cranium,  orbits,  and  nasal  fossa3,  and  has  to  do 
with  six  pairs  of  cranial  nerves.  It  resembles  a  bat  with  outstretched 
wings,  and  consists  of  a  hody^  greater  and  lesser  wings,  and  pterygoid 
processes.  It  articulates  with  twelve  bones,  all  those  of  the  cranium,  and 
five  of  the  face ;  posteriorly  with  the  occipital  and  temporals,  anteriorly 
with  the  ethmoid,  palatals,  frontal,  and  malars,  laterally  with  the  tem- 
porals, frontal,  and  parietals,  inferiorly  with  the  vomer  and  palatals,  and 
sometimes  with  the  superior  maxillae. 

The  body  is  hollowed  into  two  cavities  separated  by  the  sphenoidal 
septum^  and  opening  anteriorly  into  the  upper  and  back  part  of  the 
nasal  fossae  behind  the  superior  turbinate  bone. 

The  superior  surface  presents  in  front  the  ethmoidal  spine,  articulating 
with  the  cribriform  plate  of  the  ethmoid.  On  either  side  of  this  surface 
is  a  slight  depression  for  the  olfactory  lobe,  and  its  posterior  margin  is 
the  limhus  sphenoidalis.  Behind  this,  on  a  lower  plane,  is  the  optic 
groove^  terminating  on  either  side  in  the  ojjtic  foramen.  Next  is  the 
olivary  eminence  [tidjerculum  sellce),  and  next  the  pituitary  fossa^  or  sella 
Turcica  (Turkish  saddle):  it  is  occasionally  bounded  in  front  by  two 
middle  clinoid  processes ;  behind  is  a  square  lamina,  the  dorsum  sellce  or 
dorsum  ephippii  (back  of  saddle),  which  slopes  posteriorly  down  and 
back  into  the  basilar  groove  :  this  slope  is  the  clivus  Blumenhachii  (Blu- 
menbach's  hill). 

The  upper  angles  of  this  lamella  project  over  the  fossa  as  the  posterior 
clinoid  processes;  the  sides  are  grooved  for  the  sixth  pair  of  nerves. 
The  sides  of  the  body  present  a  winding  groove  curved  like  the  letter/ 
for  the  carotid  artery  in  the  cavernous  sinus.  Behind  its  commence- 
ment, at  the  lower  lateral  angle  of  the  dorsum  sellse,  is  the  petro.ml  pro- 
cess of  the  sphenoid,  to  fit  against  the  apex  of  the  petrous;  opposite 
this,  on  the  other  side  of  the  groove,  is  a  tongue-like  process,  the  lingida 
sphenoidalis. 

The  posterior  surface  is  quadrilateral,  and  united  to  the  basilar  process 
by  cartilage  in  early  life,  and  by  bone  after  the  fwenty-fifth  year. 


3 

3 

I 

1:^ 


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PLATE  IV. 

Fig.  1. — To  face  jxuje  44- 


Internnl  pterygoid  plate. 
JIamv.lar  process.- 


Sphenoid  Bone.     Anterior  Surface. 
Fig.  2. — To  face  page  47. 


^u^  Eihmoiditi, 


Perpendicular  Plate  of  Ethmoid  (enlarged).     Shown  by  removing  the 
Right  Lateral  Mass. 


BOXES   OF  THE   CRANIUM.  45 

The  anterior  surface  is  marked  in  the  middle  Une  by  the  sphenoidal 
crest^  which  articulates  with  the  perpendicular  plate  of  the  ethmoid. 
On  each  side  of  the  crest  is  a  mesial  and  lateral  part :  the  lateral  shows 
half-cells,  to  be  completed  by  the  ethmoid  and  orbital  plate  of  the  pala- 
tal ;  the  mesial  part  is  smooth,  and  gives  entrance  anteriorly  into  the 
sphenoidal  sinus,  and  forms  part  of  the  roof  of  the  nose. 

The  inferior  surface  presents  the  rostrum  (beak),  which  continues  the 
sphenoidal  crest  and  fits  between  the  alae  of  the  vomer. 

The  sphenoidal  turbinate  bones  (spongy  bones,  conchse  sphenoidales,  bones  of 
Berlin)  form  a  considerable  part  of  the  anterior  wall  of  the  body  of  the 
sphenoid.  They  are  curved  and  triangular,  with  apex  backward.  A  small 
portion  of  them  sometimes  appears  on  the  inner  wall  of  the  orbit  between 
the  ethmoid,  frontal,  sphenoid,  and  palate  bones. 

Each  lateral  surface  of  the  body  is  mostly  occupied  by  the  attachment 
of  the  greater  wings,  except  in  front  a  free  surface  bounds  the  sphenoidal 
fissure  and  forms  the  hindermost  part  of  the  inner  wall  of  the  orbit. 

The  small  or  orbital  wings  (processes  of  Ingrassias)  extend  horizon- 
tally outward  on  a  level  with  the  fore  part  of  the  superior  surface  of  the 
body :  the  extremity  of  each  is  pointed  and  comes  almost  into  contact 
with  the  great  wing.  The  inferior  surface  forms  the  upper  boundary  of 
the  sphenoidal  fissure  and  part  of  the  roof  of  the  orbit.  The  anterior 
border  articulates  with  the  orbital  plate  of  the  frontal ;  the  posterior  is 
free,  and  forms  the  boundary  between  the  anterior  and  middle  fossae  of 
the  skull,  and  terminates  internally  in  the  anterior  clinoid  j^^^ocess.  Be- 
tween this  clinoid  process  and  the  olivary  eminence  is  a  semicircular  notch 
in  which  the  carotid  groove  ends.  The  optic  foramen  perforates  the 
base  of  the  wing,  the  parts  above  and  below  being  called  its  roots. 

The  great  or  temporal  wings  project  out  and  up  from  the  sides  of  the 
body :  the  back  part  of  each  is  horizontal  and  fills  the  angle  between  the 
squamous  and  petrous  portions  of  the  temporal ;  from  its  extremity  pro- 
jects downward  the  spinous  process.  The  fore  part  is  vertical  and  three- 
sided,  and  lies  between  the  cranial  cavity,  the  orbit,  and  temporal  fossa. 

The  cerebral  surface  is  concave,  and  forms  part  of  the  middle  fossa  of 
the  skull. 

The  external  surface  (temporo-zygomatic)  is  divided  by  the  infratem- 
poral crest  into  a  lower  part  looking  down  into  the  zygomatic  fossa,  and 
an  upper  part  looking  out  into  the  temporal  fossa. 

The  anterior  surface  looks  forward  and  inward,  and  consists  of  the 
orbital  plate  for  the  external  wall  of  the  orbit,  and  of  a  smaller  portion 
above  the  pterygoid  process  which  looks  into  the  spheno-maxillary  fossa 
and  is  perforated  by  the  foramen  rotundum. 

The  2^osferior  border  near  the  body  bounds  the  foramen  lacerum,  and 
in  its  lateral  part  articulates  with  the  petrous,  forming  a  groove  beneath 
for  the  cartilaginous  portion  of  the  Eustachian  tube.  The  external  bor- 
der, commencing  at  the  spinous  process,  articulates  with  the  squamous, 
and  above  it  overlaps  the  anterior  inferior  angle  of  the  parietal  bone. 


46  BONES   OF   THE   HEAD. 

In  front  of  this  is  a  triangular  surface  formed  by  the  upper  margins  of 
the  cerebral,  orbital,  and  temporal  surfaces.  The  anterior  margin  artic- 
ulates above  with  the  malar :  below  this  is  a  free  horizontal  edge  separat- 
ing the  zygomatic  from  the  spheno-maxillary  surface.  Above  and  inter- 
nally the  orbital  and  cerebral  surfaces  meet  at  a  sharp  border  which 
forms  the  inferior  boundary  of  the  sphenoidal  fissure,  and  often  shows  a 
bony  projection  for  the  lower  head  of  the  external  rectus. 

The  pterygoid  (wing-like)  processes  project  downward  and  foi'ward, 
angle  of  110°  to  115°,  from  the  junction  of  the  body  and  great  wings. 
Some  consider  them  to  rise  from  two  roots,  one  representing  a  transverse 
process,  one  a  rib,  and  the  Vidian  canal,  the  costo-transverse  foramen. 
Each  consists  of  two  plates  united  in  front  and  diverging  behind,  form- 
ing the  pterygoid  fossa  for  the  origin  of  the  internal  pterygoid  muscle. 
The  external  plate  is  broad  and  extends  out  and  back,  and  gives  origin 
by  its  outer  surface  to  the  external  pterygoid  muscle.  The  internal  plate 
is  long  and  narrow,  and  prolonged  below  into  the  hamular  (hook-like) 
process,  round  which  plays  the  tendon  of  the  tensor  palati  muscle.  The 
upper  part  of  the  inner  plate  turns  in  beneath  the  body,  and  remains 
distinct  as  a  slightly  raised  edge,  the  vaginal  process,  which  meets  the 
everted  margin  of  the  vomer.  At  the  angle  of  the  vaginal  process  with 
the  internal  plate  is  a  groove  which,  with  the  sphenoidal  process  of  the 
palate,  forms  the  ptery go-palatine  canal.  Posteriorly,  at  the  base  of 
the  inner  plate,  is  the  pterygoid  tubercle,  to  the  inner  side  of  and  below 
the  Vidian  canal :  between  this  and  the  pterygoid  fossa  is  the  scaphoid 
fossa  for  the  origin  of  the  tensor  palati  muscle.  Lower  down,  on  the 
posterior  margin  of  the  plate,  is  the  processus  tuharius,  which  supports 
the  cartilage  of  the  Eustachian  tube.  Between  the  lower  ends  of  the 
plates  is  the  pterygoid  notch,  occupied  by  the  pyramidal  process  of  the 
palate  bone. 

Name  the  fissures  and  foramina  of  the  sphenoid. 

Each  half  i)resents  a  fissure,  four  foramina,  and  a  canal.  The  sjphe- 
noidal  fissure  is  the  oblique  interval  between  the  great  and  small  wings, 
closed  externally  by  the  frontal  bone.  ^  It  opens  into  the  orbit  and  trans- 
mits the  third,  fourth,  ophthalmic  division  of  the  fifth,  and  the  sixth  cra- 
nial nerves,  some  sympathetic  filaments  from  the  cavernous  plexus,  the 
orbital  branch  of  the  middle  meningeal  artery,  recurrent  branch  of  the 
lachrymal  artery,  and  the  ophthalmic  vein.  Above  and  to  the  inside  of 
this  fissure  is  the  optic  foramen,  piercing  the  base  of  the  small  wing  and 
transmitting  the  optic  nerve  and  ophthalmic  artery.  The  foramen 
rotundum  pierces  the  great  wing  below  the  sphenoidal  fissure  and  trans- 
mits the  superior  maxillary  nerve.  Behind  and  external  to  this  is  the 
foramen  ovale,  near  the  posterior  margin  of  the  great  wing,  sometimes 
incomplete :  it  transmits  the  inferior  maxillary  nerve,  the  small  menin- 
geal artery,  and  sometimes  the  small  superficial  petrosal  nerve.  The 
foramen  spinosum  pierces  the  great  wing  near  the  posterior  angle,  and 
transmits  the  middle  meningeal  artery  and  n.  spinosus,  a  recurrent  branch 


BONES   OF   THE   CRANIUM.  47 

of  the  Infraniaxillaiy.  From  the  foramen  spinosum  projects  backward  a 
thin  horizontal  sphoio-pefrosal  lamina,  which  reaches  the  upper  border 
of  the  Eustachian  canal  on  the  petrous. 

The  Vidian  canal  pierces  the  base  of  the  internal  pterygoid  plate 
antero-posteriorly ;  it  passes  from  the  foramen  lacerum  to  the  spheno- 
maxillary fossa,  transmitting  the  Vidian  nerve  and  vessels. 

A  spicule  of  bone  may  connect  the  middle  clinoid  process  (when  present) 
with  the  anterior,  forming  a  carotico-dinoid  foramen  for  the  carotid  artery. 
Interclinoid  ligaments  are  normally  present  beneath  the  dura.  The  outer 
pterygoid  plate  may  be  connected  by  bone  or  ligament  with  the  spinous 
process.  The  foramen  of  Vesalius  for  an  emissary  vein  is  sometimes  present 
on  the  inner  side  of  the  foramen  ovale.  The  canalicuhis  imiomimatus  is  some- 
times present  for  the  small  superficial  petrosal  nerve  internal  to  the  foramen 
spinosum. 

Describe  the  ethmoid  bone. 

The  ethmoid  (sieve-like)  projects  down  between  the  orbital  plates  of 
the  frontal,  and  enters  into  the  formation  of  the  cranium,  orbits,  and 
nasal  fossoe.  It  consists  of  thin  plates  enclosing  irregular  cells — a  ver- 
tical plate  and  two  lateral  masses  united  above  by  the  horizontal  cribri- 
form plate, 

It^  articulates  with  thirteen  bones — fifteen  including  the  sphenoidal 
turbinate — the  frontal,  sphenoid,  and  vomer,  the  nasals,  lachrymals, 
superior  maxillae,  palatals,  and  inferior  turbinate  bones.  The  vertical 
X)late  forms  the  upper  third  of  the  nasal  septum,  and  presents  grooves 
and  canals^  for  olfactory  nerves.  Its  superior  border  appears  in  the 
cranial  cavity  as  the  crista  galli  (cock's  comb) ;  posteriorly  this  process 
is  thin,  and  anteriorly  is  broadened  into  two  alar  processes,  between 
which  is  usually  a  groove  completing  the  foramen  caecum  with  the 
frontal.  If  the  vertical  plate  be  deflected  below  the  cribriform,  the 
crista  galU  is  inclined  in  the  opposite  direction.  The  anterior  border  of 
the  plate  articulates  with  the  nasal  spine  of  the  frontal  and  with  the 
nasal  bones ;  the  inferior  border  in  front  with  the  triangular  cartilage  of 
the  nose,  and  behind  with  the  vomer;  the  posterior  margin  with  the 
sphenoidal  crest. 

Each  lateral  mass  or  labyrinth  encloses  three  sets  of  spaces — the 
anterior,  middle,  and  posterior  ethmoidal  cells :  they  do  not  communi- 
cate with  each  other.  Externally  is  the  paper-like  orbital  plate,  or  os 
planum  (lamina  papyracea),  closing  in  the  middle  and  posterior  cells: 
it  articulates  in  front  with  the  lachrymal,  behind  with  the  sphenoid, 
above  with  the  frontal,  and  below  with  the  superior  maxilla  and  palate 
bones.  On  this  aspect  below  the  plate  is  a  groove  belonging  to  the 
middle  meatus  of  the  nose :  it  turns  up  anteriorly,  and  is  continued  by 
the  infundibuhim  through  the  anterior  ethmoidal  cells  to  the  frontal 
sinus;  the  middle  cells  open  into  the  horizontal  part  of  the  groove. 
The  lateral  mass  in  front  of  the  orbital  plate  is  covered  in  by  the  lachry 
mal :  from  this  part  the  uncinate  process  curves  back,  down,  and  out, 


48  BONES   OF   THE   HEAD. 

helping  to  close  the  orifice  of  the  antrum :  it  articulates  below  with  the 
ethmoidal  process  of  the  inferior  turbinate. 

The  inner  aspect  of  each  lateral  mass  is  in  the  outer  wall  of  the  nasal 
fossa.  Above  is  a  channel,  the  superior  meatus^  passing  from  behind  to 
about  the  middle  of  the  bone  :  it  communicates  with  the  posterior  cells. 
The  plate  overhanging  it  is  the  superior  turbinate  process  or  superior 
spongy  hone  (concha  sup. ) ;  the  space  above  that  is  in  the  roof  of  the 
nose.  Below  the  groove  is  the  inferior  turhinafe  process  of  the  ethmoid 
or  middle  spongy  ione  (concha  inf ),  rolling  convexly  toward  the  nasal 
fossa :  it  forms  the  lower  border  of  the  lateral  mass. 

Two  grooves  cross  the  upper  margin  of  the  lateral  mass,  forming  with 
the  frontal  the  two  internal  orbital  canals.  Posteriorly  the  mass  is 
ankylosed  with  the  sphenoidal  spongy  bone. 

The  cribriform  plate  occupies  the  ethmoidal  notch  of  the  frontal.  It 
presents  the  olfactory  groove  on  each  side  of  the  crista  galli  and  foramina 
for  the  olfactory  nerves ;  the  foramina  of  the  middle  set  are  few  and  are 
simple  perforations;  in  the  external  and  internal  sets  they  are  more 
numerous,  and  are  orifices  of  small  canals  which  subdivide  on  the  vertical 
plate  and  lateral  mass.  Anteriorly  is  a  fissure  close  to  the  base  of  the 
crista  galli,  and  external  to  it  a  notch  connecting  with  the  anterior  in- 
ternal orbital  canal  for  the  passage  of  the  nasal  nerve  and  anterior  eth- 
moidal artery  from  the  orbit  to  the  cranium,  and  thence  to  the  nasal 
fossa. 

BONES  OP  THE  FACE. 

Describe  the  superior  maxillary  bone. 

The  superior  maxilla  is  the  principal  bone  of  the  face,  supporting  the 
upper  teeth  of  one  side,  helping  to  form  the  hard  palate,  floor  of  orbit, 
floor  and  outer  wall  of  nasal  fossa.  There  are  a  body  and  four  processes 
for  description.  The  body  is  a  hollow  half-cylinder,  presenting  an  ex- 
ternal surface  subdivided  into  an  anterior  and  posterior,  an  internal  and 
superior ;  the  processes  are  nasal,  alveolar,  malar,  and  palatal. 

The  body  encloses  the  antrum  of  Highmore,  which  opens  into  the 
middle  meatus  of  the  nose.  The  superior  maxilla  articulates  with  nine 
or  ten  bones — with  its  fellow,  with  the  nasal, frontal,  lachrymal,  ethmoid, 
palate,  malar,  vomer,  inferior  turbinate,  and  sometimes  with  the  sphe- 
noid at  the  outer  extremity  of  the  spheno-maxillary  fissure.  The  anterior 
or  facial  surface  is  marked  below  by  eminences  corresponding  to  fangs 
of  the  teeth.  Internal  to  the  eminence  for  the  canine  is  the  incisor  or 
wyrtifonn  fossa;  external  to  it  is  the  diQQ\)QV  canine  fossa ;  above  the 
latter,  below  the  margin  of  the  orbit,  is  the  infraorbital  foramen.  The 
inner  margin  of  this  surface  is  cut  by  the  nasal  notcJi^  the  sharp  edge  of 
which  is  prolonged  into  the  anterior  nasal  sjyine. 

The  posterior  or  zygomatic  surface  looks  into  the  zygomatic  and  spheno- 
maxillary fossae :  it  presents  two  or  more  apertures  of  the  posterior  den- 
tal canals ;  below  and  posteriorly  is  a  rough  tuberosity.     At  the  junction 


N 


BONES   OF   THE   FACE.  49 

of  this  surface  with  the  nasal  and  orbital  is  a  small  triangular  space  on 
which  the  orbital  process  of  the  palate  rests,  the  palatine  trigone  (Henle). 

The  internal  or  yta^al  surface  presents  in  front  the  inferior  turbinate 
crest ;  below  it  is  the  smooth  concavity  of  the  inferior  meatus  ;  above  it 
a  small  surface  forming  the  atritim  (entry)  of  the  middle  meatus.  Be- 
hind tlie  nasal  process  is  the  lachrymal  groove,  i  inch  long,  inclined 
down  and  out,  opening  into  the  inferior  meatus ;  the  groove  is  converted 
into  the  canal  of  the  nasal  duct  by  the  lachrymal  and  inferior  turbinate. 
Behind  it  is  the  opening  of  the  antrum  ;  above  this  are  small  half-cells 
belonging  to  the  middle  ethmoidal  set.  Behind  the  opening  of  the  an- 
trum the  surface  is  rough  for  articulation  with  the  palate  bone,  and  trav- 
ersed by  a  groove  running  down  and  forward,  forming  with  the  palate 
the  posterior  palatine  canal. 

The  orbital  surface  is  triangular  and  flat ;  externally  is  a  rough  surface 
for  the  malar ;  internally  is  first  the  lachrymal  notch,  and  behind  it  a 
pretty  straight  margin  for  the  ethmoid  and  orbital  process  of  the  palate. 
The  postero-external  border  is  free  and  bounds  the  spheno-maxillary  fis- 
sure. The  infraorbital  groove  commences  well  back  on  this  surface,  lead- 
ing to  a  canal  of  the  same  name  which  opens  anteriorly  at  the  infraorbital 
foramen :  from  the  canal  are  given  off  the  anterior  and  middle  dental 
canals  in  the  substance  of  the  bone. 

The  nasal  process  projects  up,  in,  and  back ;  its  external  surface  is 
smooth ;  the  hinder  part  of  the  mner  surface  completes  the  anterior  eth- 
moidal cells ;  below  this  the  surface  is  crossed  by  the  superior  turbinate 
crest  (agger  nasi)  for  the  inferior  turbinate  process  of  the  ethmoid  (mid- 
dle spongy  bone).  The  anterior  border  articulates  ivith  the  nasal  bones 
and  above  with  the  frontal ;  posteriorly  is  a  continuation  of  the  lachrymal 
groove,  bounded  internally  by  a  sharp  edge  articulating  with  the  lachry- 
mal, and  externally  by  a  smooth  border :  where  this  border  joins  the  orbital 
surface  is  the  lachrymcd  tubercle. 

Tlie  alveolar  process  is  thick  and  hollowed  into  eight  alveoli.  The 
malar  process  is  triangular,  continuous  in  front  and  behind  with  the 
facial  and  zygomatic  surfaces  of  the  body.  Superiorly  it  is  rough  for 
the  malar :  the  inferior  border  forms  a  thick  buttress  opposite  the  first 
molar. 

The  palate  process  with  its  opposite  forms  three-fourths  of  the  hard 
palate.  ^  Above  it  is  concave  transversely,  and  forms  part  of  the  floor 
of  the  inferior  meatus.  Below  it  is  arched,  and  shows  lateral  grooves 
for  nerves  and  vessels :  its  posterior  extremity  falls  short  of  that  of  the 
alveolar  arch  and  the  space  is  filled  by  the  palate  bone.  The  inner 
border  rises  into  a  nasal  crest  which  receives  the  vomer ;  in  front  a  more 
elevated  part  is  the  incisor  crest,  prolonged  into  the  anterior  nasal  spine. 
By  the  side  of  the  incisor  crest  is  a  foramen,  becoming  a  groove :  when 
the  bones  are  united  there  is  one  orifice  below,  with  right  and  left 
branches  above,  called  the  incisor  foramina  or  foramina  of  Stenson,  for 
the  transmission  of  arteries  (Fig.  3).  The  lower  aperture  is  the  anterior 
palatine  fossa ;  in  the  middle  line,  opening  into  it,  are  the  foramina  of 
4  —A. 


50 


BONES   OF   THE   HEAD. 


Scarpa^  the  left  naso-palatine  nerve  passing  through  the  anterior  one 
and  the  right  through  the  posterior.  From  the  anterior  palatine  fossa 
are  seen  two  sutures  passing  to  the  interval  between  the  canine  and  lat- 


FiG.  3. 

\  Ccmeil 


2f  Sl^rtsorv^ 


of  Scarpa^ 


Ihslr^jpuZcaine  CctnaZ/ 


Accessortf  palaJtrrc^ 


The  Palate  and  Alveolar  Arch. 


eral  incisor  tooth ;  the  sutures  are  to  be  seen  in  the  inferior  meatus. 
They  mark  oif  the  intermaxillary  hone^^  and  include  the  whole  thickness 
of  the  alveolar  processes,  the  nasal  spine,  and  sockets  for  incisor  teeth. 
No  trace  of  the  suture  is  seen  on  the  racial  surface,  as  an  outgrowth,  the 
incisor  process,  forms  the  front  wall  of  the  incisor  sockets. 

The  maxillary  sinus,  or  antrum,  is  irregularly  pyramidal ;  the  base  is 
at  the  nasal  surface  of  the  body  and  the  apex  extends  into  the  malar 
process.  Its  aperture  is  closed  in  part  by  the  uncinate  process  of  the 
ethmoid,  the  ethmoidal  process  of  the  inferior  turbinate,  and  the  maxil- 


PLATE   V.      Fig.  I.— To  face  page  61. 
Orbital  process. 

Orbital  surface. 


Maxillary  surface. 


Superior  meatus. 
Spheno-palaline  foramen^^ 


Maxillary 
process. 


Horizontal  Plate, 
Left  Palate  Bone,  internal  view  (enlarged). 

Fiu.  2. — To  face  page  51. 
Orbital  process. 


Sphenoidal  palatine 
foramen. 

Sphenoidal  process. 
Articular  portion. 
Is  on-articular  portion. 


External  Surface, 


''^*% 


Horizontal 
Plate, 


Posterior 
nasal  spine. 


Left  Palate  Bone,  posterior  view  (enlarged). 


PLATE  VI. 

Fig.  1. — To  face  page  52. 


With  sup.  maxill.  hones  and  palate. 
Vomer. 


Fig.  2. — To  face  page  54- 


^''m 


Kight  Inferior  Turbinated  Bone,  internal  surface. 


Fig.  3. — To  face  page  54- 


Bight  Inferior  Turbinated  Bone,  outer  surface. 


BONES   OF   THE   FACE.  51 

lary  process  of  the  palate  behind ;  the  lachrymal  in  front  rarely  assists. 
The  alveolus  of  the  first  molar  is  most  prominent  in  the  floor. 

Describe  the  palate  bone. 

This  bone  is  L-shaped,  and  forms  the  back  part  of  the  hard  palate  and 
the  lateral  wall  of  the  nose  between  the  superior  maxilla  and  internal 
pterygoid  plate.  It  presents  a  horizontal,  a  vertical  plate,  and  three 
processes.  It  articulates  with  six  bones — its  fellow,  the  superior  maxilla, 
the  ethmoid,  sphenoid,  vomer,  and  inferior  turbinate.  The  horizontal 
or  palate  plate  is  concave  above  in  the  nasal  fossa ;  near  its  posterior 
border  is  a  transverse  ridge  for  the  tensor  palati  muscle.  The  posterior 
border  is  free  and  concave,  gives  attachment  to  the  soft  palate,  and  is 
prolonged  internally  into  the  posterior  nasal  or  palatine  spine^  which 
continues  the  nasal  crest  of  the  superior  maxillae  supporting  the  vomer. 
It  is  grooved  externally  by  the  p)osterior  palatine  canal.  The  vertical 
plate  is  thin  ;  its  nasal  surface  is  divided  into  two  parts  by  the  inferior 
turbinate  crest  for  the  inferior  turbinate  bone ;  the  middle  meatus  is 
above  it  and  the  inferior  below.  At  the  upper  part  is  the  superior 
turbinate  crest  for  the  middle  spongy  bone,  and  above  this  a  groove  in 
the  superior  meatus.  The  external  surface  presents  above  and  behind 
a  smooth  surface,  forming  the  inner  wall  of  the  pterygo-maxillary  fissure, 
and  leads  to  the  posterior  palatine  r/roove.  In  front  of  the  groove  the 
surface  is  applied  to  the  superior  maxilla  and  sends  the  maxillary  pro- 
cess forward.  Behind  the  groove  the  surface  articulates  below  with  the 
maxilla  and  above  with  the  pterygoid  process. 

The  pyramidal  process  or  tuberosity  juts  out  behind  and  fits  in  between 
the  pterygoid  plates :  it  presents  posteriorly  a  smooth  middle  district  en- 
tering into  the  pterygoid  fossa ;  internal  to  it  is  a  groove  for  the  internal 
pterygoid  plate,  and  externally  a  rough  area  for  the  external  plate. 
Fart  of  the  tuberosity  appears  in  the  zygomatic  fossa.  Inferiorly,  close 
to  the  horizontal  plate,  are  the  posterior  and  external  accessory  palatine 
canals. 

The  orbital  process  rests  on  the  anterior  margin  of  the  vertical  plate : 
it  has  five  surfaces,  three  articular,  and  two,  the  superior  and  external, 
are  free. 

The  superior  surface  forms  the  posterior  angle  of  the  floor  of  the 
orbit ;  the  external  looks  into  the  sphenomaxillary  fossa ;  the  anterior 
articulates  with  the  maxilla,  the  internal  with  the  ethmoid,  and  the  pos- 
terior with  the  sphenoid.  The  process  is  usually  hollow,  and  completes 
a  posterior  ethmoidal  cell  or  may  open  into  the  sphenoidal  sinus. 

The  sphenoidal  process  curves  up  and  in  irom  the  posterior  part  of 
the  vertical  plate ;  it  has  three  surfaces :  the  superior  is  in  contact  with 
the  under  surface  of  the  body  of  the  sphenoid,  and  is  grooved  for  the 
ptery go-palatine  canal;  the  internal  surface  looks  into  the  nasal  fossa 
and  touches  the  ala  of  the  vomer ;  the  external  looks  into  the  spheno- 
maxillary fossa. 


52  BONES   OF   THE   HEAD. 

The  spheno-palathie  notch  is  between  these  two  processes,  converted 
by  the  body  of  the  sphenoid  into  a  foramen  of  the  same  name. 

The  posterior  palatine  canal  may  be  wholly  confined  to  the  palate  bone. 
The  spheno-palatine  notch  may  be  converted  to  a  foramen  by  union  of  the 
sphenoidal  and  orbital  processes.  The  orbital  process  may  be  enlarged  by  a 
separate  ossification  from  the  ethmoid  or  sphenoid. 

Describe  the  vomer. 

The  vomer  (ploughshare)  is  thin  and  quadrilateral,  and  placed  verti- 
cally between  the  nasal  fossae.  The  upper  and  posterior  borders,  the 
anterior  and  inferior,  are  of  nearly  equal  lengths.  It  articulates  with 
six  bones — the  sphenoid,  ethmoid,  two  palate,  two  superior  maxillary — 
and  with  the  septal  cartilage  of  the  nose. 

Each  surface  presents  a  groove  leading  the  naso-palatine  nerve  to  the 
foramen  of  Scarpa.  The  superior  border  divides  into  two  alae,  which 
receive  the  rostrum  of  the  vomer  between  them ;  each  ala  meets  the 
vaginal  process  of  the  sphenoid  and  the  sphenoidal  process  of  the 
palate. 

There  are  usually  three  vomero-basilar  canals — a  median,  between  ala  and 
rostrum  for  nutrient  vessels ;  an  upper  lateral  one,  between  the  body  of 
sphenoid  and  root  of  vaginal  process,  carrying  vessels  to  the  sphenoidal  cells  ; 
a  lower  lateral  one,  between  the  body  of  sphenoid  and  sphenoidal  process  of 
palate,  carrying  vessels  and  nerves  from  the  nasal  and  spheno-maxillary  fos- 
sae to  the  upper  pharynx. 

The  anterior  border  is  grooved  in  its  lower  half  for  the  septal  cartilage ; 
in  its  upper  half  it  is  ankylosed  on  one  or  both  sides,  usually  the  right, 
with  the  perpendicular  plate  of  the  ethmoid.  At  the  inferior  anterior 
angle  is  a  short  vertical  edge  to  fit  in  behind  the  incisor  crest  of  the 
maxillae :  from  its  upper  end  a  process  runs  forward  in  the  groove  of 
the  crest,  and  from  its  lower  end  a  point  may  project  down  between  the 
incisor  foramina.  The  inferior  border  articulates  with  the  nasal  crest  of 
the  maxillae  and  palate  bones  :  the  posterior  border  is  thin  and  free  and 
separates  the  posterior  narcs. 

Describe  the  malar  bone. 

This  cheek-bone  separates  the  orbit  from  the  temporal  fossa  and  ar- 
ticulates with  four  bones — the  frontal,  sphenoid,  temporal,  and  superior 
maxillary.  It  is  quadrangular,  with  the  angles  directed  vertically  and 
horizontally  :  it  may  be  thought  of  as  formed  of  a  triangular  orbital  plate 
united  at  a  sharp  angle  to  a  quadrangular  malar  plate.  The  outer  sur- 
face presents  a  little  below  the  centre  the  malar  tuberosity^  and  above 
this  the  orifice  of  the  malar  canal.  The  inner  surface  is  concave,  looks 
into  the  temporal  and  zygomatic  fossae,  and  presents  a  roughness  for  ar- 
ticulation with  the  superior  maxilla.  The  upper  angle  or  frontal  process 
is  serrated  for  the  external  angular  process  of  the  frontal.  The  temporal 
border  behind  this  is  sinuous  and  continuous  with  the  upper  border  of 
the  zygoma. 


BONES   OF  THE   FACE.  53 

The  posterior  angle  or  tenmoral  process  has  the  zygoma  resting  upon 
and  articulating  with  it.  The  postero-inferior  border,  the  masseteric^ 
completes  the  lower  edge  of  the  zygomatic  arch  ;  the  antero-inferior 
.  border,  maxillarij^  and  a  rough  part  of  the  inner  surface,  articulate  with 
the  malar  process  of  the  superior  maxilla.  The  orbital  border  is  exca- 
vated, and  forms  a  great  part  of  the  orbital  margin,  ending  internally 
just  above  or  inside  the  infraorbital  foramen.  From  this  the  orbital 
process  projects  back,  forming  the  fore  part  of  the  outer  wall  of  the  orbit, 
articulating  with  the  great  wing  of  the  sphenoid.  On  the  orbital  surface 
are  the  openings  of  two  canals — the  temporal  opening  on  the  temporal 
surface,  and  the  malar  opening  on  the  facial :  they  transmit  the  tem- 
poro-malar  branches  of  the  superior  maxillary  nerve. 

A  horizontal  suture  may  divide  the  bone  into  two  unequal  parts.  The 
canals  may  have  a  common  opening  on  the  orbital  surface.  There  may  be  a 
marginal  process  at  the  upper  part  of  the  temporal  border  (more  often  on  the 
right  side)  for  attachment  of  a  band  of  temporal  fascia.  The  anterior  ex- 
tremity of  the  spheno-maxillary  fissure  may  be  completed  in  one  of  three 
ways:  by  the  malar  in  more  than  half  the  cases,  by  the  articulation  of  the 
sphenoid  with  the  superior  maxilla,  or  by  a  Wormian  bone. 

The  antrum  of  Highmore  may  extend  into  the  malar. 

Describe  the  nasal  bones. 

The  two  form  the  bridge  of  the  nose,  and  each  articulates  with  four 
bones — the  frontal,  superior  maxillary,  ethmoid,  and  its  fellow.  They 
are  narrow  and  thick  above,  broader  and  thinner  below.  They  articulate 
above  with  the  inner  part  of  the  nasal  notch  of  the  frontal. 

The  inferior  border  is  free,  and  gives  attachment  to  the  lateral  nasal 
cartilage :  it  usually  has  a  small  notch  near  the  inner  end.  The  ex- 
ternal border  is  longest,  and  articulates  by  means  of  small  teeth  with  the 
nasal  process  of  the  superior  maxilla. 

The  internal  border  meets  its  fellow  in  a  somewhat  irregular  internasal 
suture,  which  commonly  deviates  to  one  side  at  the  upper  end.  Pos- 
teriorly the  two  form  a  crest  which  rests  from  above  down  on  the  nasal 
process  of  the  frontal,  the  vertical  plate  of  the  ethmoid,  and  the  septal 
nasal  cartilage.  The  facial  surface  is  convex  below  and  concave  above, 
and  presents  vascular  foramina. 

The  posterior  surface  is  concave,  and  a  little  external  to  its  centre  is  a 
longitudinal  groove  for  the  nasal  nerve. 

These  bones  are  relatively  large  in  white  races,  small  and  flat  in  the  black 
and  yellow  races.  The  internasal  suture  is  obliterated  in  apes.  There  may 
be  small  internasal  bones  at  the  lower  extremity  of  the  internasal  suture. 

Describe  the  lachrymal  bone. 

The  lachrymal,  or  os  unguis^  is  a  thin  scale  like  a  finger-nail  at  the  an- 
terior and  inner  part  of  the  orbit.  It  articulates  with  four  bones — 
frontal,  ethmoid,  superior  maxilla,  and  inferior  turbinate.  Its  external 
surface  is  divided  by  a  vertical  ridge,  the  lachrymal  crest :  in  front  of  it 


54  BONES   OF   THE    HEAD. 

is  the  lachrymal  groove,  and  this  part  is  prolonged  below  as  the  descend- 
ing proce^H  to  articulate  with  the  inferior  turbinate  ;  behind  the  crest  the 
surmce  is  smooth  and  forms  part  of  the  orbit,  and  it  is  produced  below 
into  the  hamular  process^  which  comes  forward  in  the  lachrymal  notch 
of  the  superior  maxilla  and  bounds  the  outer  side  of  the  orifice  of  the 
nasal  duct.  The  internal  surface  is  a  depressed  furrow  completing  above 
some  of  the  anterior  ethmoidal  cells,  and  below  it  looks  into  the  middle 
nasal  meatus. 

This  bone  may  be  absent,  perforated,  or  divided  into  pieces ;  the  hamular 
process  may  be  wanting,  small,  or  so  long  as  to  extend  upon  the  face,  A 
separate  ossicle  may  take  its  place,  the  lesser  lachrymal  bone. 

Describe  the  inferior  turbinate  bone. 

The  inferior  turbinate  or  spongy  bone  projects  like  a  shell  into  the 
nasal  cavity,  separating  the  middle  from  the  inferior  meatus.  Its  con- 
vexity looks  in  and  its  lower  margin  is  rolled  on  itself  Its  attached 
margin  articulates  in  front  with  the  inferior  turbinate  crest  of  the  supe- 
rior maxilla,  and  then  ascends  abruptly  as  the  lachrymal  process  to  com- 
plete the  lachrymal  canal.  Behind  this,  and  nearer  the  back  than  the 
the  front,  the  bone  is  folded  down  as  the  maxillary  process^  looking 
over  the  aperture  of  the  antrum,  and  forming  part  of  its  inner  wall :  on 
the  upper  border  of  this  process  is  the  ethmoidal  process,  which  articu- 
lates with  the  uncinate  of  the  ethmoid.  Posteriorly,  the  bone  is  attached 
to  the  inferior  turbinate  crest  of  the  palate :  the  posterior  extremity  is 
elongated  and  pointed,  the  anterior  flat  and  broad. 

The  bone  articulates  with  the  superior  maxilla,  lachrymal,  ethmoid, 
and  palate.  No  muscle  is  attached  to  it.  The  negro  may  have  four  tur- 
binate bones. 

Describe  the  inferior  maxillary  bone. 

The  lower  jaw,  or  mandible,  is  the  strongest  bone  of  the  face,  and 
articulates  with  the  glenoid  fossae  of  the  temporals.  It  consists  of  a 
curved  horizontal  portion  or  body  and  two  ascending  branches  or  rami. 
The  body  shows  in  front  a  faint  vertical  ridge,  the  symphysis  of  two 
originally  distinct  pieces :  this  expands  into  the  mental  protuberance, 
which  becomes  prominent  on  each  side  inferiorly  as  the  mental  tubercles. 
The  superior  or  alveolar  border  is  hollowed  out  into  sockets  for  teeth. 
The  inferior  border,  or  base,  is  thick  and  rounded,  and  projects  beyond 
the  superior.  Below  the  incisor  teeth  is  the  mc/so?-/os.9a;  more  exter- 
nally is  the  mental  foramen  midway  between  the  upper  and  lower  bor- 
ders, under  the  interval  between  the  two  bicuspids :  it  is  the  anterior 
opening  of  the  dental  canal.  Below  the  foramen  the  external  oblique 
line  runs  up  and  back  from  the  mental  tubercle  to  the  anterior  margin 
of  the  ramus.  The  deqp  surface  of  the  body  presents  inferiorly  near  the 
symphysis  an  oval  fossa  for  the  attachment  of  the  digastric  muscle: 
above  it  are  the  mental  spines,  the  lower  being  a  median  ridge  for  the 
genio-hyoid  muscles,  and  the  upper  a  pair  oi  tubercles  for  the  genio- 


THE   SKULL   AS   A    M^HOLE.  55 

hyoglossi :  there  may  be  four  tubercles  ( 1 1 )  or  two  (  •  •  )  or  a  vertical 
ridge  (I)  or  one  prominence  (  • ).  Above  them  a  small  foramen  pene- 
trates the  bone  and  above  this  a  narrow  median  groove  marks  the  sym- 
physis. Below  the  mental  spines,  and  passing  up  and  back  to  the  ramus, 
is  the  internal  oblique  line  or  mylo-hyoid  ridge^  for  the  mylo-hyoid  muscle 
and  a  slip  of  the  superior  constrictor  of  the  pharynx.  Above  this  line  is 
a  fossa  for  the  sublingual  gland,  and  below  it  another  for  the  submax- 
illary. 

The  ramus  is  thinner  than  the  body,  and  where  its  posterior  border 
meets  the  base  it  forms  the  slightly  everted  angle.  The  external  surface 
is  flat,  and  near  the  angle  it  shows  oblique  lines  for  tendinous  attach- 
ment of  the  masseter  muscle.  At  the  centre  of  the  internal  surface^  on 
a  level  with  the  crowns  of  the  molar  teeth,  is  the  inferior  dental  foramen^ 
leading  to  the  dental  canal:  the  inner  margin  of  the  foramen  is  sharp 
anteriorly,  and  called  the  lingula  mandihidce.  Beginning  at  the  notch 
behind  the  hngula  is  the  mylo-hyoid  groove  (sometimes  a  canal),  termi- 
nating below  the  hinder  end  of  the  mylo-hyoid  ridge.  Behind  this  is  a 
roughness  for  the  internal  pterygoid  muscle.  On  the  upper  border  of 
the  ramus  are  two  processes — the  condyle  for  articulation  and  the  coro- 
noid  for  muscular  attachment :  they  are  separated  by  the  semilunar  or 
sigmoid  notch.  The  condyle  passes  up  from  the  posterior  part  of  the 
ramus,  supported  on  a  constricted  neck^  on  the  front  of  which  internally  is 
a  depression  for  the  external  pter3^goid  muscle.  One-third  inch  (8  mm. )  be- 
low the  articular  surface  there  may  be  an  external  tubercle  for  the  external 
lateral  ligament.  The  condyle  is  convex,  transversely  elongated,  and  the 
axes  of  the  two  would  meet  at  the  anterior  margin  of  the  foramen  mag- 
num. The  coronoid  process  passes  up  from  the  fore  part  of  the  ramus,  in- 
clined out  and  somewhat  beak-shaped :  by  its  apex,  sharp  margins,  and 
inner  surface  it  gives  attachment  to  the  temporal  muscle. 

The  anterior  border  of  the  ramus  shows  three  oblique  ridges — an  ex- 
ternal one  to  the  end  of  the  external  oblique  line  ;  internal  to  that  is  a 
groove  bounded  posteriorly  by  a  ridge  passing  from  the  internal  oblique 
line  to  the  middle  aspect  of  the  coronoid;  at  the  lower  part  of  the 
groove,  extending  a  short  distance  to  the  outer  side  of  the  alveolus,  is 
the  third  or  buccal  line. 

The  lower  jaw  consists  of  a  thick  shell  of  compact  tissue  enclosing  cancel- 
lous tissue ;  the  dental  canal  in  its  posterior  two-thirds  lies  close  to  the  inner 
compact  layer ;  it  is  prolonged  beyond  the  mental  foramen  under  the  canine 
and  incisor  teeth.  There  may  be  two  dental  canals.  The  angle  of  the  jaw 
in  the  adult  is  about  120°,  infancy  140°  or  more ;  in  old  and  toothless  jaws  it 
is  increased.  These  changes  are  due  to  development,  absorption  of  alveolar 
arch,  and  strength  of  masseter  muscles. 

THE   SKULL   AS   A  WHOLE. 
Describe  the  sutures. 
The  skull-bones  are  closely  fitted  by  uneven  edges,  there  being  inter- 


56  BONES   OF   THE   HEAD. 

posed  a  little  fibrous  tissue  continuous  with  the  periosteum ;  the  den- 
tations are  confined  to  the  external  table,  the  edges  of  the  inner  table 
lying  only  in  apposition.  The  lower  jaw  has  a  movable  articulation, 
diiFering  from  the  others.  The  sutures  around  the  parietal  bones  have 
special  names :  between  the  two  is  the  sagittal^  behind  them  the  lamh- 
doid,  in  front  of  them  the  coronal. 

All  the  sutures  may  be  arranged  in  three  groups — a  median  longi- 
tmiinal,  a  lateral  longitudinal,  and  a  vertical  transverse.  The  first  con- 
sists of  the  sagittal,  and  in  the  infant  the  frontal ;  the  second  begins  in 
the  median  line  in  front,  and  includes  on  each  side  the  fronto-nasal, 
fronto-maxillary,  fronto-lachrymal,  fronto-ethmoidal,  fronto-malar,  fronto- 
sphenoidal,  spheno-parietal,  squamo-parietal,  and  masto-parietal ;  the 
third^  comprises  the  coronal  and  spheno-squamous,  the  lambdoid  and 
occipito-mastoid,  and  also  the  transverse  sutures  at.  the  base  of  the 
skull. 

Sometimes  the  great  wing  of  the  sphenoid,  the  parietal,  the  squama,  and 
the  frontal  bones  do  not  meet,  and  the  short  spheno-parietal  suture  is  not 
formed ;  the  frontal  and  squama  unite  in  a  vertical  fronto-temporal  suture 
continuing  the  coronal:  this  is  the  rule  in  the  gorilla  and  chimpanzee.  In 
this  situation  is  often  developed  the  epipteric  bone. 

After  about  thirty  years  of  age  many  sutures  close,  union  taking  place  on 
the  inner  surface  first :  the  parts  to  close  first  are  the  sagittal  suture  between 
the  parietal  foramina  and  the  lower  ends  of  the  coronal  suture. 

THE   WORMIAN   BONES. 

These,  ossa  triquetra,  ossa  suturarum,  are  irregular  ossifications  between 
cranial  bones  rarely  found  in  the  face.  They  are  usually  symmetrical,  and 
are  most  common  in  the  lambdoid  suture,  occupying  the  place  of  the  superior 
angle  of  the  occipital  bone ;  may  be  at  either  anterior  angle  of  the  parietals. 
They  usually  include  only  one  plate  of  the  skull. 

The  ossiculum  jugular e  may  be  found  at  the  jugular  foramen. 

EXTERNAL  SURFACE  OP  THE  SKULL. 

The  external  surface  may  be  divided  into  superior,  inferior,  anterior, 
and  lateral  regions. 

Describe  the  superior  region. 

This  extends  from  the  supraorbital  margins  to  the  superior  curved 
line  of  the  occiput,  bounded  laterally  by  the  temporal  lines.  It  is  a 
smooth,  convex  surface  covered  by  muscle  and  aponeurosis.  The  great- 
est transverse  diameter  of  the  skull  is  at  the  junction  of  the  posterior 
and  middle  thirds — viz.  5f  inches  (140  mm.) ;  the  greatest  longitudinal 
diameter  from  the  under  margin  of  frontal  bone  to  the  external  occi- 
pital protuberance  is  6*  inches  (170  mm. ).  As  the  head  is  usually  held 
it  makes  an  angle  of  20°  with  the  horizon. 

Describe  the  anterior  region. 
This  region  presents  the  openings  of  the  orbits,  the  bridge  of  the  nose, 


EXTERNAL  SURFACE   OF   THE  SKULL.  57 

below  tliat  the  anteinor  nasal  aperture  {apertura  pyriformis),  presenting 
the  anterior  nasal  spine  below.  Below  the  aperture  are  the  incisor  fossae 
of  the  upper  jaw,  below  the  orbits  the  canine  fossae,  and  external  to 
them  the  malar  prominences.  The  lower  jaw  completes  the  skeleton  of 
the  face  with  its  incisor  fossae,  mental  prominence,  etc. 

In  a  nearly  vertical  line  on  either  side  are  three  foramina  for  the  exit 
of  some  part  of  the  three  divisions  of  the  fifth  cranial  nerve — viz.  the 
supraorbital,  infraorbital,  and  mpntal.  There  are  also  the  malar  for- 
amina on  the  malar  bone. 

The  nose  is  rarely  placed  in  the  centre  of  the  face,  and  the  nasal  aper- 
ture is  often  unsymmetrical,  a  deflection  of  the  septum  occurring  toward 
the  wider  half 

Describe  the  orbits. 

The  orbits  are  pyramidal  fossae,  somewhat  quadrilateral,  with  their 
bases  turned  out  and  forward  :  their  inner  walls  are  nearly  parallel,  and 
their  outer  walls  diverge  at  nearly  right  angles  to  each  other.  Each  is 
formed  of  seven  bones,  or  eleven  for  the  two — the  frontal,  sphenoid, 
malar,  superior  maxillary,  lachrymal,  ethmoid,  and  palate.  The  roof 
of  each  is  formed  by  the  orbital  plate  of  the  frontal  and  small  wing  of 
the  sphenoid;  the  floor  by  the  malar,  superior  maxilla,  and  orbital  plate 
of  the  palate;  the  inner  wall  by  the  nasal  process  of  the  superior 
maxilla,  the  lachrymal,  ethmoid,  and  body  of  the  sphenoid ;  the  outer 
wall  by  the  malar  and  great  wing  of  the  sphenoid.  The  sphenoidal 
fissure  at  its  inner  part  occupies  the  apex  of  the  orbit;  its  outer  ex- 
tremity lies  between  the  roof  and  outer  wall. 

The  optic  foramen  is  internal  to  and  above  the  fissure.  In  the  angle 
between  the  external  wall  and  floor  is  the  spheiio-maxillary  fissure^ 
bounded  by  the  palate,  superior  maxilla,  malar,  and  sphenoid  bones: 
it  leads  into  the  spheno-maxillary  fossa  at  its  back  part  and  zygomatic 
fossa  at  its  fore  part.  Passing^  forward  from  the  margin  of  this  fissure 
is  the  commencement  of  the  infraorbital  canal.  On  the  inner  wall  in 
front  is  the  lachrymal  groove,  leading  to  the  canal  of  the  nasal  duct,  and 
farther  back,  between  the  frontal  and  ethmoid,  are  the  anterior  and 
posterior  internal  orbital  canals.  At  the  inner  margin  of  the  roof  is  the 
supraorbital  foramen  or  notch.  Within  the  external  angular  process  is 
the  lachrymal  fossa^  and  on  the  outer  wall  are  the  temporal  and  malar 
canals. 

Describe  the  lateral  region  of  the  skull. 

This  presents  from  behind  forward  the  mastoid  portion,  the  mastoid 
foramen,  the  external  auditory  meatus,  the  glenoid  fossa  with  condyle 
of  lower  jaw,  eminentia  articularis,  coronoid  process,  and  zygomatic  arch. 
Above  this  arch  is  the  temporal  fossa,  and  below  it,  separated  by  the 
infratemporal  crest,  is  the  zygomatic  fossa. 

The  temporal  fossa,  occupied  by  the  temporal  muscle,  is  bounded 
above  by  the  temporal  crest  of  the  frontal  and  the  lower  temporal  line 


68  BONES   OF  THE   HEAD. 

of  the  parietal :  the  latter  runs  into  the  supramastoid  crest,  and  that 
into  the  zygomatic  arch. 

The  zygomatic  or  wfratemj^oral  fossa  contains  a  part  of  the  temporal 
muscle,  the  external  and  internal  pterygoids,  the  internal  maxillary  artery, 
and  the  inferior  maxillary  nerve.  Some  of  its  boundaries  are  indefinite  : 
externally  is  the  ramus  of  the  lower  jaw ;  superiorly  the  great  wing  of  the 
sphenoid,  showing  the  foramen  ovale  and  spinosum,  also  a  small  part  of 
the  squamous  portion  of  the  temporal ;  anteriorly  is  the  lower  part  of 
the  malar  and  zygomatic  surface  of  the  superior  maxilla ;  the  inferior 
limit  is  the  extremity  of  the  external  pterygoid  plate  and  alveolar  border 
of  the  superior  maxilla.  The  inner  wall  is  formed  by  the  external  ptery- 
goid plate  ;  the  posterior  limit  is  the  eminentia  articularis  and  posterior 
border  of  the  pterygoid  plate. 

Inferiorly  the  pterygoid  process  approaches  close  to  the  superior 
maxilla,  but  is  prevented  from  meeting  by  the  pyramidal  process  of  the 
palate.  Above  they  are  separated  by  the  pterygo-maxUlan/  fissure^ 
leading  into  the  spheno-maxiUanj  fossa.  Running  at  right  angles  to  the 
fissure  is  the  spheno-m axillary  fissure  opening  into  the  orbit. 

Describe  the  spheno-maxillary  fossa. 

This  is  a  small  triangular  space  at  the  angle  of  junction  of  the  above- 
named  fissures,  placed  beneath  the  apex  of  the  orbit.  It  is  bounded 
above  by  the  body  of  the  sphenoid,  in  front  by  the  superior  maxilla, 
behind  by  the  base  of  the  pterygoid,  and  internally  by  the  vertical  plate 
of  the  palate.  It  has  three  fissures  terminating  in  it — the  sphenoidal, 
spheno-maxillary  and  pterygo-maxillary.  It  communicates  with  four 
fossae — the  orbital,  nasal,  zygomatic,  and  middle  fossa  of  the  base  of 
the  skull ;  and  has  opening  into  it  five  foramina — three  from  behind, 
the  foramen  rotundum,  the  Vidian,  and  the  pterygo-palatine  canals; 
internally  is  the  spheno-palatine  foramen,  and  inferiorly  the  posterior 
palatine  canals,  and  occasionally  the  accessory  posterior  palatine  canals. 

Describe  the  external  base  of  the  skull. 

("Base  of  skull"  properly  means  base  of  the  cranium,  and  does  not 
include  the  facial  bones ;  we  have  followed,  however,  the  usual  descrip- 
tion, and  include  the  inferior  maxilla.) 

It  is  divisible  into  three  parts — anterior,  middle,  and  posterior.  The 
anterior  division  consists  of  the  palate,  alveolar  arches,  and  body  of  the 
inferior  maxilla.  It  is  traversed  longitudinally  by  a  median  suture,  and 
transversely  by  that  between  the  maxillary  and  palate  bones.  In  front 
is  the  anterior  palatine  fossa^  with  the  four  foramina  opening  into  it ; 
farther  back  are  the  under  surface  of  the  tuberosity  of  the  palate,  the 
apertures  of  the  posterior  and  external  palatine  canals,  and  the  posterior 
nasal  spine. 

The  middle  division  extends  back  to  the  foramen  magnum,  and  is 
called  the  guttural  fossa  (relating  to  the  throat).  In  the  mid-line  is  the 
basilar  process,  and  in  front  of  that  the  body  of  the  sphenoid  covered 


EXTERNAL   SURFACE   OF   THE   SKULL.  59 

by  the  alae  of  the  vomer.  On  each  side  the  petrous  portion  reaches  to 
the  extremity  of  the  basilar  process,  and  between  the  petrous  and 
squamous  is  the  back  part  of  the  great  wing  of  the  sphenoid.  In  front 
are  the  posterior  nares  or  choance  (funnels),  separated  by  the  vomer, 
bounded  above  by  the  sphenoid,  below  by  the  horizontal  plates  of  the 
palate  bones,  and  laterally  by  the  internal  pterygoid  plates.  On  each 
side  are  the  ptery go- palatine  and  Vidian  canals,  the  scaphoid  and  ptery- 
goid fossae.  A  line  froul  the  external  pterygoid  plate  to  the  spine  of  the 
sphenoid  separates  this  surface  from  the  zygomatic  fossa :  internal  to  this 
line  is  the  groove  for  the  cartilaginous  part  of  the  Eustachian  tube. 
Between  the  apex  of  the  petrous,  the  basilar  process,  and  the  sphenoid 
is  the  foramen  lacerum.  (This  is  the  only  foramen  properly  called 
"lacerated.")  This  with  the  petro-basilar  fissure  is  filled  with  fibrous 
tissue,  and  may  contain  Wormian  bones.  Passing  back  and  out  from 
this  is  the  petro-sphenoidal  fissure,  the  styloid  and  vaginal  processes, 
and  the  stylo-mastoid  foramen  ;  more  internally  are  the  anterior  condylar 
foramina  and  the  jugular  fossa.  This  fossa,  is  divided  into  three  com- 
partments by  processes  of  dura  mater.  The  inferior  petrosal  sinus  is  in 
the  anterior  one,  the  lateral  sinus,  some  ascending  pharyngeal  and  occi- 
pital arteries  in  the  posterior  one,  and  the  ninth,  tenth,  and  eleventh 
cranial  nerves  in  the  middle  one. 

Other  points  have  been  described  with  the  temporal  bone. 

The  posterior  division  presents  on  either  side  of  the  foramen  magnum 
the  occipital  condyle,  jugular  process,  occipital  sulcus,  digastric  fossa, 
and  mastoid  process.  Behind  the  foramen  magnum  is  the  tabular  part 
of  the  occipital  up  to  the  superior  curved  line.  Into  this  posterior  divis- 
ion are  inserted  all  the  muscles  running  up  to  the  skull  from  the  ribs, 
spines,  and  transverse  processes. 

Henle  describes  for  base  of  skull  the  base  of  the  cranial  bones :  the  foramen 
magnum  is  where  the  vertebral  canal  broadens  out  into  the  cranium ;  behind 
it  is  the  part  corresponding  to  the  vertebral  arches,  in  front  the  part  corre- 
sponding to  the  vertebral  body.  The  line  of  separation  passes  through  the 
mastoid  and  jugular  processes,  the  condyles,  and  the  foramen  magnum.  In 
front  of  this  line  are  two  other  regions :  the  "  middle  girdle  "  nearly  corre- 
sponds to  the  middle  fossa  of  the  interior ;  its  anterior  border  goes  on  either 
side  from  the  pharyngeal  spine,  in  front  of  the  pterygoid  process  to  the  outer 
extremity  of  the  crista  orbitalis,  which  is  the  upper  border  of  the  spheno- 
maxillary fissure. 

The  anterior  portion  in  front  of  the  pharyngeal  spine  forms  the  roof  of  the 
"vegetative  tube." 

Describe  the  interior  of  the  cranium. 

The  inner  table  presents  impressions  for  cerebral  convolutions.  The 
thickness  of  the  skull-cap,  or  calvaria,  is  J  to  }  inch.  The  base  of  the 
skull  varies  in  thickness,  thinnest  at  the  cribriform  and  orbital  plates, 
where  there  is  no  diploe ;  also  thin  in  the  inferior  occipital  fossa,  in  the 
squama,  and  glenoid  fossa.  The  inner  surface  of  the  calvaria  is  dome- 
like, formed  by  the  frontal,  parietal,  and  occipital  bones.     It  is  marked 


60  BONES  OF  THK   HEAD. 

by  the  superior  longitudinal  sulcus,  small  meningeal  grooves,  and  Pac- 
chionian fossae.   The  only  apertures  are  the  inconstant  parietal  foramina. 

Describe  the  internal  base  of  the  skull. 

This  surface  is  divided  into  three  fossae — anterior,  middle,  and  poste- 
rior. 

The  anterior  fossa  is  formed  by  the  orbital  plates  of  the  frontal,  the 
cribriform  of  the  ethmoid,  the  small  wings  and. part  of  the  body  of  the 
sphenoid :  it  supports  the  frontal  lobes  of  the  cerebrum.  It  is  convex 
laterally,  with  a  hollow  over  the  cribriform  plate,  where  the  crista  galU 
stands  up  separating  the  olfactory  grooves.  There  is  here  the  foramen 
caecum,  the  olfactory  foramina,  openings  of  the  internal  orbital  canals, 
and  the  foramen  for  the  nasal  nerve. 

The  middle  fossa  is  on  a  lower  level  than  the  anterior,  and  consists  of 
a  median  and  two  lateral  parts.  The  median  part  is  narrow,  presenting 
the  olivary  eminence,  the  sella  Turcica,  and  limited  behind  by  the  dor- 
sum sellae.  Laterally  is  the  great  wing  of  the  sphenoid,  the  squama, 
and  antero-internal  surface  of  the  petrous  portion.  This  lodges  the  tem- 
poral lobe  of  the  cerebrum.  The  foramina  present  are  the  optic,  sphe- 
noidal fissure,  foramen  rotundum,  ovale,  spinosum,  lacerum,  and  hiatus 
Fallopii. 

The  posterior  fossa  is  deeper  and  larger  than  the  others,  and  lodges 
the  cerebellum,  medulla,  and  pons.  The  occipital  bone,  the  petrous 
and  mastoid  portions,  postero-inferior  angle  of  the  parietal,  and  body  of 
the  sphenoid  enter  into  it.  In  the  centre  is  the  foramen  magnum,  and 
on  each  side,  in  a  nearly  vertical  line,  are  the  anterior  condylar  foramen, 
jugular  foramen,  and  internal  auditory  meatus.  Behind  the  jugular 
foramen  is  the  posterior  condylar  (if  present),  and  higher  up  the  mas- 
toid foramen,  both  opening  into  the  lateral  sulcus.  By  the  internal 
auditory  meatus  the  facial  and  auditory  nerves,  the  portio  intermedia, 
and  the  auditory  vessels  leave  the  cranium. 

What  grooves  are  there  for  blood-vessels  ? 

That  for  the  middle  meningeal  artery  commences  at  the  foramen 
spinosum,  and  passes  anteriorly  to  the  great  wing  of  the  sphenoid,  and 
posteriorly  upon  the  squama  and  parietal.  There  is  also  the  groove  for 
tlie  internal  carotid  artery  on  the  side  of  the  body  of  the  sphenoid,  the 
groove  for  the  superior  longitudinal  sinus  terminating  at  the  internal 
occipital  protuberance,  those  for  the  lateral  sinuses,  and  others  for  the 
superior  and  inferior  petrosal  sinuses  on  the  petrous  portion. 

Describe  the  nasal  cavities  and  communicating  air-sinuses. 

The  7iasal  fossce.  are  placed  one  on  each  side  of  a  median  vertical  sep- 
tum. They  open  in  front  by  the  anterior  nasal  aperture  and  behind  by 
the  posterior  nares.  They  communicate  with  the  sinuses  of  the  frontal, 
ethmoid,  sphenoid,  and  superior  maxillary  bones.  They  are  narrow 
transversely,  especially  above.     The  internal  icall,  or  septum  nasij  is 


INTERNA  li   SURFACE   OF   THE   SKULL.  61 

formed  by  the  perpendicular  plate  of  the  ethmoid,  the  vomer,  nasal 
spine  of  the  frontal,  crests  of  the  nasal,  rostrum  of  sphenoid,  crests  of 
the  maxillary,  and  palate  bones.  There  is  an  angular  deficiency  in  front, 
filled  by  the  septal  cartilage,  which  usually  deviates  to  one  side. 

The  roof  is  horizontal  in  the  middle  part  and  sloping  in  front  and  be- 
hind. The  middle  part  is  formed  by  the  cribriform,  the  fore  part  by  the 
nasal  and  frontal  bones,  the  back  part  by  the  body  of  the  sphenoid,  the 
ala  of  the  vomer,  and  sphenoidal  process  of  the  palate.  In  the  angle 
formed  by  the  cribriform  and  body  of  the  sphenoid  is  the  siiheno-eth- 
moidal  recess :  the  sphenoidal  sinus  opens  upon  its  posterior  wall. 

11\Q  floor  is  formed  by  the  palate  processes  of  the  maxillary  and 
palate  bones;  it  is  smooth  and  concave  transversely,  and  shows  the 
orifice  of  the  incisor  foramen.  The  external  wall  is  formed  by  the 
nasal,  superior  maxillary,  lachrymal,  ethmoid,  inferior  turbinate,  palate, 
and  internal  pterygoid  plate.  The  superior  and  inferior  turbinate 
processes  of  the  ethmoid  and  the  inferior  spongy  bone  overhang  the 
three  meatuses.  The  superior  meatus  is  very  short,  and  placed  be- 
tween the  superior  and  inferior  turbinate  processes;  into  it  open  in 
front  the  posterior  ethmoidal  cells,  and  behind  the  spheno-palatine 
foramen.^  The  middle  meatus  is  above  the  inferior  spongy  bone,  and 
communicates  with  the  anterior  and  middle  ethmoidal  cells,  with  the 
maxillary  sinus,  and  in  front  by  the  infundibulum  with  the  frontal 
sinus.  The  inferior  meatus^  longer  than  the  others,  lies  between  the 
inferior  spongy  bone  and  the  floor  of  the  cavity ;  in  front  is  the  orifice 
of  the  nasal  duct. 

The  Air- Sinuses. 

These  communicate  with  the  nasal  cavities  by  narrow  orifices :  with 
the  exception  of  the  maxillary  sinus  (antrum)  they  are  not  present  at 
birth.  In  old  age  they  increase  in  size  by  absorption  of  neighboring 
cancellated  tissue.  The  antrum  begins  to  be  formed  about  the  fourth 
month.  The  frontal,  ethmoidal,  and  sphenoidal  excavate  their  respective 
bones  in  childhood,  and  at  puberty  undergo  a  great  enlargement.  Their 
purpose  may  be  for  resonance.  They  have  been  sufiUciently  described 
with  the  different  bones. 

OSSIFICATION   OF   THE   BONES   OF   THE   HEAD. 

Ossiiacatioas  at  the  base  of  the  cranium  take  place  for  the  most  part  in  car- 
tilage ;  those  of  the  roof  of  the  skull  and  of  the  face  originate  in  membrane, 
excepting  the  inferior  turbinate  and  part  of  the  lower  jaw.  The  diploe  and 
air-sinuses  are  absent  at  first. 

The  ocdpHal  bone  consists  of  four  pieces  at  birth — a  basilar,  tabular,  and  two 
condylar  parts.  Tlie  basilar  and  condylar  parts  have  each  one  nucleus ;  in 
the  tabular  part  there  are  usually  four,  the  upper  pair  deposited  in  membrane 
and  representing  the  interparietal  bone  of  animals.  This  subdivision  may 
exist  in  the  human  skull. 

The  parietal  hone  begins  to  ossify  in  membrane  at  the  seventh  week  :  it  has 


62  BONES   OF   THE   HEAD. 

two  centres,  which  speedily  unite  into  one  mass  at  the  position  of  the  future 
parietal  eminence.  The  radiating  ossification  leaves  a  notch  in  front  of  the 
upper  posterior  angle,  giving  rise  when  united  to  its  fellow  to  the  sagittal  fon- 
tanelle.  This  closes  during  foetal  life,  but  the  parietal  foramina  are  remains 
of  the  interval.  Sometimes  a  parietal  fissure  persists.  The  two  centres  may 
develop  separately. 

The  frontal  bone  is  developed  from  two  centres  in  membrane,  appearing  at 
the  seventh  week.  At  birth  the  bone  consists  of  two  lateral  portions :  the 
frontal  suture  ossifies  from  below  upward,  usually  during  the  second  year. 
The  frontal  sinuses  appear  about  the  seventh  year  and  increase  to  old  age. 

The  fontanelles  are  membranous  intervals  between  the  incomplete  angles 
of  the  parietal  and  neighboring  bones,  They  are  six  in  number — two  median 
and  four  lateral.  The  anterior  is  quadrangular,  placed  between  four  bones, 
with  its  most  acute  angle  pointing  toward  the  nose;  the  posterior  is  trian- 
gular, is  filled  at  birth,  but  the  bones  are  freely  movable.  The  lateral  ones, 
are  irregular  intervals  at  the  inferior  angles  of  the  parietal.  All  traces  of 
them  should  disappear  before  the  age  of  four. 

The  temporal  bone  late  in  foetal  life  consists  of  three  parts — squamo-zygo- 
matic,  petro-mastoid,  and  tympanic — developed  from  ten  centres  :  the  squamo- 
zygomatic  is  developed  in  membrane  from  a  single  centre.  From  the  squa- 
mosal a  post-auditory  process  grows  down  between  the  tympanic  and  petro- 
mastoid  portions,  and  forms  the  upper  part  of  the  mastoid  division  of  the  bone. 
In  the  third  month  a  nucleus  appears  in  the  membranous  wall  of  the  tym- 
panum and  forms  the  tympanic  ring,  an  imperfect  circle  open  above  and  en- 
closing the  tympanic  membrane.  The  petro-mastoid,  or  ear-capsule,  is  de- 
veloped in  cartilage. 

The  styloid  process  is  formed  from  two  centres  in  cartilage :  the  one  near 
the  extremity  remains  small  till  puberty,  not  joining  the  other  till  adult  life 
or  remaining  separate.  At  birth  the  mastoid  portion  is  flat,  the  antrum  is 
present,  the  glenoid  fossa  shallow,  the  tympanic  ring  and  membrane  are  even 
with  the  outer  surface  of  the  bone.  The  external  auditory  meatus  is  devel- 
oped by  an  outward  projection  of  the  tympanic  ring,  commencing  as  two 
tubercles  :  these  meet  on  the  floor  of  the  meatus,  enclosing  a  foramen  which 
is  not  obliterated  till  the  fifth  year.  This  part  always  remains  thin,  or  a  small 
aperture  may  persist. 

The  sphenoid  is  divided  in  the  foetus  into  a  post-sphenoid  part,  to  which 
the  sella  Turcica,  great  wings,  and  pterygoids  belong,  and  a  presphenoid  part, 
which  includes  the  body  in  front  of  the  olivary  eminence  and  the  small 
wings.  It  has  twelve  centres  in  all,  one  for  each  pterygoid  plate,  each  lin- 
gula,  each  carotid  groove.  The  sphenoidal  spongy  bones  begin  to  ossify  at  the 
fifth  month.  They  entirely  surround  the  sphenoidal  sinus  by  the  third  year ; 
then  their  upper  and  inner  parts  absorb.  They  are  ankylosed  first  to  the 
ethmoid  (fourth  year) ;  hence  some  regard  them  as  parts  of  that  bone ;  they 
join  the  sphenoid  at  the  ninth  to  twelfth  year. 

The  ethmoid  has  three  centres,  one  for  each  lateral  mass  and  one  for  the  ver- 
tical plate ;  the  cribriform  comes  from  all  three  sources. 

The  superior  maxilla,  clavicle,  and  lower  jaw  begin  to  ossify  at  about  the 
same  time,  fifth  to  the  seventh  week.  The  number  of  centres  is  uncertain,  but 
there  seem  to  be  four  pieces — a  malar  portion,  orbito-facial,  palatine,  and  a 
premaxillary  for  the  bone  carrying  the  incisor  teeth.  The  antrum  appears  at 
the  fourth  month.  The  infraorbital  canal  begins  as  a  groove,  which  is  closed 
by  the  growing  over  of  the  outer  margin :  a  fine  suture  remains  to  indicate 
the  line  of  meeting. 

The  palate  bone  has  a  single  centre. 


EXTERNAL   SURFACE   OF   THE   SKULL.  63 

The  vomer  has  two  nuclei  in  membrane ;  they  unite  below,  but  above  and 
in  front  form  two  laminae. 

The  nasal  and  lachrymal  bones  each  have  a  separate  centre :  the  lateral  car- 
tilage of  the  nose  continues  up  beneath  the  nasals ;  it  subsequently  disappears. 

The  malar  bone  has  three  centres :  a  continued  separation  of  one  of  them 
gives  rise  to  a  bipartite  bone  occasionally  seen. 

The  inferior  turbinate  has  a  single  centre  in  cartilage  at  the  fifth  month. 

The  inferior  maxillary  bone  is  developed  in  the  fibrous  tissue  investing 
Meckel's  cartilage:  thefergest  part  is  formed  in  membrane  outside  this  car- 
tilage. A  small  part  of  the  body  near  the  symphysis  ossifies  directly  from 
Meckel's  cartilage ;  the  condyle,  part  of  the  ramus,  and  the  angle  also  ossify 
in  cartilage,  the  last  not  connected  with  Meckel's,  which  runs  up  to  the  fissure 
of  Glaser  continuous  with  the  slender  process  of  the  malleus,  and  it  eventu- 
ally forms  the  internal  lateral  ligament  of  the  lower  jaw. 

What  are  some  of  the  points  of  difference  between  human  and 
animal  skulls? 

(1)  The  proportionally  large  expansion  of  the  cranial  bones  in  the  human 
skull ;  (2)  the  smaller  development  of  the  face  and  jaws,  all  of  which  are 
under  the  brain-case;  (3)  adaptation  of  the  cranium  to  the  erect  posture. 
The  occipital  condyles  are  at  a  point  about  -^  of  the  distance  from  the 
posterior  to  the  anterior  extremity  of  the  head,  but  this  part  is  heavier 
than  the  anterior,  and  therefore  nearly  balanced.  The  foramen  magnum 
looks  down  ;  in  quadrupeds  it  is  posterior  and  looks  back  ;  in  anthropoid  apes 
it  is  intermediate  in  direction.  The  downward  openings  of  the  nostrils, 
forward  aspect  of  the  orbits,  vertical  forehead,  and  oval  face  are  in  strong 
contrast  with  the  small  cranium  and  strong  crests  of  the  animal.  In  late 
years  the  vertebrate  theory  of  the  skull  tends  to  be  abandoned. 

What  are  some  of  the  various  forms  of  skull  ? 

According  to  Age :  in  the  foetus  the  posterior  part  is  large  and  the  face  is  not 
one-eighth  of  the  cranial  bulk,  while  in  the  adult  it  is  one-half.  The  skull 
grows  rapidly  during  the  first  seven  years;  at  puberty  there  is  a  second  period 
of  growth  affecting  face  and  air-sinuses. 

Sexual  Differences:  the  female  skull  is  smaller,  smoother,  and  lighter  than 
the  male ;  the  cranial  cavity  is  less  by  one-tenth. 

Race  Differences :  the  capacity  normally  varies  from  60  to  110  cubic  inches 
(1000  cc.  to  1800  cc),  with  an  average  in  all  races  of  85  cubic  inches  (1400  cc). 

Skulls  exceeding  87  cubic  inches  (1450  cc.)  are  megacephalic— Europeans 
and  Eskimos. 

Skulls  below  80  cubic  inches  (1350  cc.)  are  microcephalic— Australians. 

Skulls  between  80  and  87  cubic  inches  (1350  and  1450  cc.)  are  mesocephalic— 
Chinese. 

What  are  the  names  of  certain  fixed  points  on  the  skull  ? 

Alveolar  point,  centre  of  upper  alveolar  arch. 
Subnasal  point,  middle  of  anterior  nasal  aperture. 
Nasion,  middle  of  naso-frontal  suture. 

Ophryon,  middle  of  that  supraorbital  line  which  separates  the  face  from  the 
cranium. 

Bregma,  point  of  junction  of  coronal  and  sagittal  sutures. 
Obelion,  point  in  the  sagittal  suture  between  the  parietal  foramina. 
Lambda,  point  of  junction  of  sagittal  and  lambdoid  sutures. 
Occipital  point,  median  point  of  occiput  most  removed  from  glabella. 


64  .  BONES  OF  THE  UPPER  EXTREMITY. 

InioHj  external  occipital  protuberance. 

Opisthion,  middle  of  posterior  margin  of  foramen  magnum. 

JBasion,  middle  of  anterior  margin  of  foramen  magnum. 

Pterion,  spheno-parietal  suture. 

Lower  stephanion,  where  lower  temporal  line  crosses  the  coronal  suture. 

Upper  stephanion,  where  the  upper  temporal  line  crosses  the  coronal  suture. 

Asterion,  lateral  angle  of  occipital  bone. 

Auricular  point,  Qentre  of  orifice  of  external  auditory  meatus. 

What  are  some  of  the  measurements  of  the  cranium  ? 

Maximum  circumference  (horizontal),  21.7  inches  (550  mm.);  minimum, 
17.7  inches  (450  mm.) ;  average  in  adult  European  male,  20.5  inches  (525 
mm.),  in  female,  19.5  inches  (500  mm.). 

The  proportion  of  the  breadth  to  the  length  on  a  scale  of  100  is  the  cephalic 
nidex : 

Skulls  with  a  breadth-index  above  80  are  brachycephalic. 

Skulls  with  a  breadth-index  from  75  to  80  are  mesaticephalic. 

Skulls  with  a  breadth-index  below  75  are  dolichocephalic. 

The  breadth  is  usually  taken  as  four-fifths  the  length. 

The  gnathic  index  expresses  the  degree  of  projection  of  the  jaws.  Similarly, 
there  are  the  nasal  index,  orbital  index,  etc.  Irregularities  of  form  are  a  result 
of  too  early  ossification  of  sutures :  scaphocephaly  is  a  result  of  obliterated 
sagittal  suture;  acrocephaly  is  due  to  obliterated  coronal  suture;  plagiocephaly 
is  oblique  deformity. 

BONES  OP   THE  UPPER  EXTREMITY. 

Shoulder  j  ^„^Iv^,^]^  [  5  forming  shoulder-girdle. 

Arm  (brachium),  humerus. 
Upper  limb,  \  Forearm  (antibrachium),  radius  and  ulna. 

( carpus. 
Hand  (manus)  <  metacarpus. 

(phalanges. 

THE    SHOULDER. 
Describe  the  clavicle. 

The  clavicle  (key)  passes  out,  back,  and  sUghtly  upward  from  the  sum- 
mit of  the  sternum  to  the  acromion,  and  connects  the  upper  limb  to  the 
trunk.  It  is  curved  like  the  letter/  for  purposes  of  elasticity  and  ad- 
mission of  vessels  behind  it.  The  inner  curve  is  convex  forward,  and 
occupies  two-thirds  of  the  bone :  this  part  is  prismatic.  The  outer  third 
of  the  bone  is  concave  in  front  and  is  flattened  from  above  down. 

The  superior  surfaces  of  these  two  portions  are  continuous ;  the  infe- 
rior surfaces  are  continuous ;  the  anterior  border  of  the  outer  portion 
runs  into  the  anterior  surface  of  the  inner ;  and  the  posterior  border  of 
the  outer  is  continuous  with  the  posterior  surface  of  the  inner.  The 
superior  surface  is  broad  externally  and  largely  subcutaneous ;  at  its  cen- 
tre it  may  present  a  canal  for  the  supraclavicular  nerve ;  the  sterno-cleido- 


THE   SHOULDER. 


^^^pLUB^ 


mastoid  is  attached  to  the  inner  part.     The  anterwr  surface  is  reduced 
to  a  rough  border  on  the  outer  portion,  where  it  jives  attachment  to  the 
deltoid,  and  mav  present  a  deltoid  tubercle.     Tfifi  PV^tori^iH|i«j«i<)r  J*  ^  1 
attached  to  the 'inner  half.  I  *-""wUN,  Mi  Ui  | 

The  posterior  surface  is  a  border  externally  aid  gives  attachment  to 
the  trapezius.     In  the  middle  of  this  surface  is  Ihe  orifice  of  a  medul- 
lary canal  directed  outward.     (In  bones  having  bu\)ig^secondary  centr^^^ 
the  medullary  artery  runs  from  it. )     Internally  thi^ra^^ce  gives  j 
attachment  to  the  sterno-hyoid  muscle.  ^  ^^w!^E,  ^^^jl^ 

The  inferior  surface  shows  internally  a  rough  'im'pYeSSf9nimt^!ostal 
tuberosity  about  1  inch  long,  for  the  rhomboid  ligament ;  internal  to  it  is 
a  small  facet  for  articulation  with  the  cartilage  of  the  first  rib  ;  external 
to  it,  a  groove  passing  beyond  the  middle  third  for  the  subclavius  mus- 
cle :  the  groove  may  show  a  longitudinal  ridge  for  an  intermuscular  sep- 
tum. On  the  posterior  border,  at  the  junction  of  the  outer  and  middle 
thirds,  is  the  conoid  tubercle  (scapular  tuberosity),  and  passing  out  and 
forward  from  it  the  trapezoid  line. 

The  sternal  end  is  thick  and  projects  in  an  angle  down  and  backward, 
its  triangular  concavo-convex  surface  looking  a  little  downward  and  for- 
ward. The  scapular  end  is  so  bevelled  as  to  rest  upon  the  acromion,  the 
small  articular  surface  looking  down  and  out :  this  end  is  normally  a 
little  higher  than  the  acromion  on  which  it  rests. 

This  bone  is  a  fulcrum  to  enable  muscles  to  give  lateral  motion  to  the  arm : 
it  is  absent  in  animals  whose  fore  limbs  are  used  only  for  progression — e.  g. 
horse  and  bear ;  in  carnivora  it  is  not  attached  to  bone ;  it  is  the  furculum  or 
*'  wish-bone "  of  birds.  The  female  clavicle  is  smoother  and  more  slender 
than  the  male.  The  right  clavicle  is  usually  rougher  and  shorter  than  the 
left.  It  is  developed  from  two  centres :  one  is  the  earliest  in  the  body  to  ap- 
pear, fifth  week,  and  the  secondary  centre  at  the  sternal  end  is  the  last  in  the 
body  to  appear,  twentieth  year. 

Describe  the  scapula. 

The  scapula  (spade)  extends  from  the  second  to  the  seventh  rib  or 
seventh  interspace.  It  is  attached  to  the  trunk  only  by  muscles,  is  ar- 
ticulated with  the  clavicle,  and  from  it  is  suspended  the  humerus  in  the 
shoulder-joint:  its  posterior  border  is  about  1  inch  from,  and  parallel 
with,  the  vertebral  spines ;  its  anterior  surface  looks  forward,  down,  and 
in.  The  bone  consists  of  a  large  triangular  blade  or  body,  and  two  pro- 
cesses, the  coracoid  and  spine,  and  presents  for  examination  two  surfaces, 
three  borders,  and  three  angles.  The  anterior  surface,  or  venter,  pre- 
sents the  subscapidar  fossa,  marked  by  three  or  four  converging  oblique 
lines,  giving  attachment  to  tendinous  intersections  of  the  subscapular 
muscle.  The  deepest  part  of  the  fossa  is  the  subscapular  angle,  where 
the  bone  seems  bent  on  itself,  so  that  the  thickest  part  of  the  muscle  is 
perpendicular  to  the  plane  of  the  glenoid  cavity,  and  can  act  most  advan- 
tageously. Separated  from  this  fossa  are  two  flat  surfaces,  one  at  the 
upper  angle  and  one  at  the  lower :  with  the  line  connecting  them  close  to 
the  vertebral  border  they  give  attachment  to  the  serratus  magnus  muscle. 
5— A. 


66  BONES  OF  THE  UPPER  EXTREMITY. 

The  posterior  surface^  or  dorsum^  is  divided  by  the  spine  into  two 
unequal  fossae,  the  supraspinous  and  wfraspinous.  The  supraspinatus 
muscle  rises  from  the  inner  two-thirds  of  the  upper  fossa.  The  lower 
fossa  is  marked  near  the  centre  by  a  convexity  corresponding  to  the 
concavity  of  the  venter ;  on  either  side  of  this  is  a  groove,  the  external 
one  being  deep  and  bounded  by  the  axillary  border.  Near  the  inner 
border  are  short  lines  for  intermuscular  septa  of  the  infraspinatus  mus- 
cle, which  rises  from  the  inner  two-thirds  and  covers  the  outer  third. 
Along  the  outer  part  of  this  surface  is  a  ridge  passing  down  and  back  to 
the  inner  border,  about  1  inch  above  the  inferior  angle :  it  gives  attach- 
ment to  the  aponeurosis  between  the  infraspinatus  and  teres  muscles.  On 
the  upper  third  of  the  narrow  surface  between  this  line  and  the  axillary 
border  is  a  groove  for  the  dorsalis  scapulae  vessels ;  the  middle  third  and 
part  of  the  upper  give  attachment  to  the  teres  minor.  Below  this,  in- 
cluding the  inferior  angle,  is  a  raised  surface  for  the  teres  major,  over 
which  the  latissimus  dorsi  glides  or  attaches  a  few  fibres.  An  oblique 
line  separates  the  origins  of  the  two  teres  muscles. 

The  S27i)ie  of  the  scapula  is  a  triangular  plate  projecting  back  and  up 
from  the  dorsum.  Beginning  near  the  upper  fourth  of  the  vertebral 
border,  it  passes  up  across  the  doi*sum  to  the  middle  of  the  neck  of  the 
scapula,  and  turns  forward  into  the  acromion  process.  The  upper  and 
lower  surfaces  are  concave  and  form  parts  of  the  two  dorsal  fossae.  It 
has  two  unattached  borders,  a  posterior  subcutaneous  one  and  an  exter- 
nal axillary  one.  The  former  rises  from  the  vertebral  border  by  a  tri- 
angular surface,  over  which  a  tendon  of  the  trapezius  glides  as  it  passes 
to  its  insertion  into  a  rough  tubercle  beyond.  (This  tubercle  is  very  large 
in  animals. )  The  rest  of  this  border  is  rough  and  serpentine,  and  gives 
attachment  by  a  superior  lip  to  the  trapezius,  by  an  inferior  lip  to  the 
deltoid.  The  external  border  is  short,  smooth,  and  concave,  enclosing 
the  great  scapular  notch. 

The  acromion  process  projects  out  and  forward  over  the  glenoid  fossa : 
it  is  compressed  from  above  down ;  its  superior  surface  is  rough,  subcu- 
taneous, and  continuous  with  the  prominent  border  of  the  spine.  An- 
teriorly on  its  inner  border  is  an  oval  articular  facet  for  the  clavicle :  to 
this  border  is  attached  the  trapezius,  to  the  outer  border  the  deltoid, 
marked  by  three  or  four  tubercles  for  tendinous  septa.  This  outer 
border  terminates  posteriorly  in  the  acromial  angle.  The  coraco- 
acromial  ligament  is  attached  to  the  apex  of  the  acromion. 

The  coracoid  process  rises  at  fii-st  almost  vertically  from  the  upper 
border  of  the  head,  compressed  from  before  backward :  it  then  bends  at 
a  right  angle  forward  and  outward.  Superiorly,  toward  its  base,  is  the 
origin  of  the  conoid  ligament,  and  the  trapezoid  rises  from  an  oblique 
line  running  forward  and  outward.  The  coraco-acromial  ligament  is  at- 
tached to  the  outer  border,  the  conjoined  tendon  of  the  coraco-brachialis 
and  biceps  to  its  apex,  and  the  pectoralis  minor  to  its  inner  border.  The 
tip  of  the  coracoid  is  about  one  and  a  half  inches  distant  from  the  apex 
of  the  acromion. 


THE   ARM.  67 

The  external  angle  of  the  scapula  is  the  thickest  part  of  the  bone :  it 
is  called  the  head,  supported  on  a  neck.  The  head  bears  the  glenoid 
cavity :  this  is  slightly  concave,  looks  outward,  forward,  and  slightly  up- 
ward. It  is  pyriform,  with  its  narrow  end  above,  and  measures  If  inches 
by  J  \  inches  (40  mm.  by  30  mm.).  Above  it  is  a  supraglenoid  tubercle 
for  the  long  head  of  the  biceps.  The  "anatomical  neck"  is  the  part 
just  behind  the  head. 

The  superior  angle  of  the  scapula  is -thin  and  rounded,  and  gives  at- 
tachment to  some  fibres  of  the  levator  anguli  scapulae. 

The  inferior  angle  is  thick  and  rough  for  the  teres  major  attachment, 
sometimes  the  latissimus  dorsi. 

The  superior  border  is  shortest,  and  extends  from  the  superior  angle 
down  to  the  coracoid,  at  the  base  of  which  is  the  suprascapular  or 
coraco-scapular  notch.  A  line  through  the  suprascapular  and  great 
scapular  notches  marks  the  "surgical  neck"  of  the  bone. 

The  axillary  border  is  the  thickest.  Beneath  the  glenoid  fossa  is  a 
rough  tubercle  or  ridge,  infraglenoid^  over  an  inch  long,  for  the  long 
head  of  the  triceps.  On  the  ventral  aspect  of  this  border  is  a  longitu- 
dinal groove  from  which  the  subscapular  muscle  rises  in  part. 

The  vertebral  border  is  the  longest,  and  gives  attachment  above  the 
triangular  surface  at  the  apex  of  the  spine  to  the  levator  anguli  muscle, 
opposite  the  triangular  surface  to  the  rhomboideus  minor,  and  below 
this  to  the  rhomboideus  major. 

The  body  of  the  scapula  is  mostly  thin  and  translucent,  and  has  no  can- 
cellated tissue  in  those  spots.  Vascular  foramina  pierce  the  upper  and  lower 
surfaces  of  the  spine  and  the  anterior  surface  near  the  neck.  The  human 
scapula  is  remarkable  for  its  length.  All  mammals  possess  scapulae.  The 
coracoid  reaches  to  the  sternum  in  birds. 

The  bone  is  developed  from  seven  centres  and  is  ossified  in  two  principal  parts, 
one  for  the  body  and  one  for  the  coracoid,  which  represents  the  large  coracoid 
bone  of  lower  vertebrates.  The  various  epiphyses  should  be  joined  to  the 
bone  at  the  age  of  twenty-five.  Sometimes  the  acromion  and  spine  do  not 
unite,  and  a  joint  with  hyaline  cartilage  and  synovial  membrane  may  here 
be  present. 

THE   ARM. 

Describe  the  humerus. 

The  arm-bone  extends  from  the  shoulder  to  the  elbow.  It  is  divisible 
into  an  upper  extremity,  including  head,  neck,  great  and  small  tuber- 
osities, a  shaft,  and  inferior  extremity,  which  includes  condyles,  epi- 
condj^les,  and  articular  surface.  The  head  forms  one-third  of  a  sphere 
of  ^\  inches  (32  mm.)  radius,  but  the  margin  is  not  a  true  circle :  a  line 
from  the  upper  part  of  the  articular  surface  down  and  back  to  the  lower 
part  is  2  inches  (50  mm.).  A  transverse  diameter  at  right  angles  to  this 
is  If  inches  (44  mm.).  The  head  is  directed  up,  in,  and  a  little  back- 
ward, and  makes  an  angle  of  140°  with  the  shaft.     The  "anatomical 


6S  BONES  OF  THE  UPPER  EXTREMITY. 

neck ' '  is  the  slight  constriction  at  the  circumference  of  the  articular  sur- 
face ;  the  "  surgical  neck  "  is  below  the  tuberosities. 

The  great  tuberosity  is  a  thick  projection  starting  up  from  the  external 
surface  of  the  shaft.  It  is  marked  above  by  three  facets,  the  upper  for 
the  supraspinatus  tendon,  the  next  for  the  infraspinatus,  and  the  lowest 
for  the  teres  minor,  which  also  is  attached  to  the  shaft  to  the  extent  of 
1  inch.  Separated  from  this  tuberosity  by  the  hidpital  groove  (inter- 
tubercular  sulcus,  f  inch  (10  mm.)  broad)  is  the  small  tuhet^osity^  looking 
forward  and  inward  and  giving  attachment  to  the  subscapularis. 

The  shaft  is  thick  and  cylindrical  above,  expanded  transversely  and 
three-sided  below.  It  is  divided  into  external,  internal,  and  posterior 
surfaces  by  anterior  and  lateral  borders.  (Henle  describes  it  as  having 
two  surfaces  and  two  borders.)  Superiorly  is  the  bicipital  groove  lodg- 
ing the  long  tendon  of  the  biceps  and  a  branch  of  the  anterior  circum- 
flex artery.  This  groove,  descending,  is  bounded  by  rough  margins,  the 
external  or  pectoral  ridge  (spina  tuberculi  majoris)  for  the  pectoralis 
major  muscle,  and  the  internal  for  the  latissimus  dorsi  and  teres  major 
muscles :  these  muscular  attachments  end  at  the  junction  of  the  upper 
with  the  lower  three-fourths. 

The  anterior  border  is  the  pectoral  ridge  continued  to  the  coronoid  de- 
pression below.  It  becomes  rounded  and  smooth  below,  and  gives  at- 
tachment to  the  brachialis  anticus  muscle. 

The  inner  border  is  the  inner  bicipital  ridge  continued  to  the  inner 
condyle,  called  below  the  internal  supracondylar  ridge.  About  the 
centre  of  this  border  is  a  rough  linear  mark  for  the  coraco-brachialis 
muscle,  and  just  below  it  the  orifice  of  the  medullary  canal  directed 
downward. 

The  external  border  runs  from  the  back  part  of  the  great  tuberosity 
to  the  external  condyle.  Its  centre  is  traversed  by  the  broad  spiral 
groove.^  hmited  above  by  the  deltoid  eminence  and  below  by  the  external 
supracondylar  ridge^  The  ridge  gives  origin  by  its  upper  two-thirds  to 
the  supinator  longus  muscle;  hence  it  is  called  the  supinator  ridge^ 
which  is  very  large  in  burrowing  animals :  its  lower  third  attaches  the 
extensor  carpi  radialis  longior.  The  posterior  lip  of  either  supracondylar 
ridge  is  for  the  triceps,  and  a  middle  portion  for  intermuscular  septa. 
The  external  surface  presents  near  its  middle  the  deltoid  eminence. 

The  internal  surface  is  narrow  above,  and  forms  the  bicipital  groove; 
near  its  centre  is  the  insertion  of  the  coraco-brachialis.  Below  this  level 
the  external  and  internal  surfaces  are  occupied  by  the  brachialis  anticus. 

The  posterior  surface  is  twisted,  so  that  its  upper  part  is  directed  a 
little  inward,  its  lower  part  backward  and  outward.  It  is  nearly  all 
covered  by  the  external  and  internal  heads  of  the  triceps,  which  are 
separated  by  the  spiral  groove  running  down  and  out.  At  the  upper 
part  of  this  groove  is  generally  a  second  medullary  foramen  for  a  branch 
of  the  superior  profunda  artery. 

The  inferior  extremity  is  flattened  from  before  backward  and  curved 


THE   ARM.  69 

slightly  forward.  The  two  condyles  include  the  articular  surface,  sepa- 
rated by  a  rounded  ridge ;  the  inner  condyle  is  five-sixths  articular. 
The  prominent  tuberosities  situated  on  either  condyle  are  the  epicon- 
dyles^  developed  from  separate  centres.  The  internal  epicondyle  is  the 
more  prominent  one,  is  inclined  backward,  and  forms  posteriorly  a  shal- 
low groove  for  the  ulnar  nerve.  It  gives  attachment  to  the  pronator 
radii  teres  and  the  common  tendon  of  the  superficial  pronato-flexor  mus- 
cles of  the  forearm. 

The  external  condyle  presents  (1)  the  epicondyle,  which  gives  origin 
to  some  of  the  supinato-extensor  muscles  of  the  forearm ;  (2)  below  and 
internal  to  this  on  the  condyle  a  small  impression  for  the  anconeus ;  and 
(3)  a  pit  for  the  external  lateral  ligament. 

The  inferior  articular  surface  is  divided  into  two  parts :  the  external 
part,  rounded  and  directed  forward,  is  the  capitellum  for  articulation 
with  the  radius ;  it  does  not  extend  at  all  on  the  posterior  surface.  In- 
ternal to  it  is  a  groove  for  the  inner  margin  of  the  head  of  the  radius. 
The  internal  portion,  or  trochlea,  articulates  with  the  ulna,  and  extends 
from  the  anterior  to  the  posterior  surface  of  the  bone ;  the  external  bor- 
der is  rounded  and  corresponds  to  the  internal  between  the  radius  and 
ulna.  The  internal  border  is  thick  and  prominent.  Anteriorly  these  mar- 
gins are  inclined  down  and  inward,  posteriorly  up  and  outward,  so  that 
the  groove  is  obliquely  inclined  from  without  inward,  and  if  continued 
would  form  the  thread  of  a  screw.  The  external  part  of  the  trochlea  is 
the  segment  of  a  sphere,  the  internal  part  the  segment  of  a  truncated 
cone  with  base  internal ;  at  the  junction  of  the  cone  and  sphere  is  the 
groove. 

Above  the  trochlea  posteriorly  is  the  olecfranon  fossa,  above  it  ante- 
riorly the  coronoid  fossa :  the  thin  plate  between  them  may  be  perforated 
by  the  supratrochlear  foramen.  This  occurs  more  often  in  the  lower 
races  of  man  and  in  the  gorilla.  Above  the  capitellum  is  the  radial 
fossa  for  the  head  of  the  radius  in  flexion. 

The  average  length  of  the  adult  male  humerus  is  13  inches,  female,  12 
inches.  It  is  nearly  one-fifth  the  height  of  the  individual.  The  right  hume- 
rus with  the  radius  is  usually  i  to  f  inches  longer  than  the  left ;  no  differ- 
ence at  birth. 

The  shaft  of  the  humerus  is  twisted  through  about  135°.  The  twist  is  seen 
at  the  spiral  groove,  "  groove  of  torsion,"  which  does  not  exist  in  the  foetus ; 
this  allows  the  hand  to  serve  the  purposes  of  the  head  and  mouth.  A  small 
hooked  supracondylar  process  is  sometimes  found  about  2  inches  above  the 
inner  epicondyle.  A  fibrous  band  connects  it  to  the  inner  epicondyle  and 
gives  origin  to  the  pronator  radii  teres  muscle ;  through  the  arch  beneath 
pass  the  median  nerve  and  brachial  artery. 

Kemains  of  this  foramen  are  seen  in  a  fibrous  band  connected  with  the 
pronator  muscle  in  about  45  per  cent,  of  cases. 

The  humerus  is  developed  from  seven  centres ;  the  upper  epiphysis  unites 
last. 


70  BONES   OF   THE   UPPER   EXTREMITY. 

.  THE  FOREARM. 

Describe  the  ulna. 

This  is  the  internal  of  the  two  bones  of  the  forearm.  A  line  passing 
from  the  tuberosity  of  the  humerus  through  the  capitellum  touches  the 
lower  end  of  the  ulna.  It  is  the  arm-bone,  while  the  radius  is  the  hand- 
bone. 

The  ripper  extremity  presents  two  processes  and  two  articular  concav- 
ities. The  great  sigmoid  cavity^  articulating  with  the  trochlea,  looks 
upward  and  forward,  and  is  bounded  above  by  the  olecranon  and  below 
by  the  coronoid  processes ;  it  is  concave  from  above  down,  and  is  trav- 
ersed by  a  longitudinal  ridge  which  is  a  half-circle  of  f  inch  (10  mm.) 
radius.  The  part  external  to  the  ridge  is  broad  and  convex  above,  the 
part  internal  is  broad  and  concave  below.  A  slight  constriction  is  seen 
across  the  middle  of  the  cavity.  Continuous  with  it  is  the  small  sigmoid 
cavity  on  the  outer  side  of  the  base  of  the  coronoid :  it  is  concave  from 
before  backward  for  the  head  of  the  radius.  The  olecranon  terminates 
in  front  in  a  beak  which  overhangs  the  great  sigmoid  cavity ;  behind  it 
is  a  rectangular  tuberosity,  forming  the  point  of  the  elbow.  It  has  supe- 
riorly a  ligamentous  district,  next  a  bursal,  and  next  a  tendinous  one  for 
the  triceps.  The  posterior  surface  of  the  olecranon  is  triangular  and  sub- 
cutaneous, and  continuous  with  the  posterior  border  of  the  ulna.  The 
extremity  of  the  coronoid  process  is  sharp  and  pointed.  Its  superior  sur- 
face is  a  part  of  the  great  sigmoid  cavity.  At  the  inner  part  of  the  junc- 
tion of  the  coronoid  to  the  shaft  of  the  ulna,  also  to  the  tuberosity  of 
ulna  at  the  angle  of  junction,  is  attached  the  brachialis  anticus  muscle, 
not  into  the  process.  Arising  from  the  process  is  one  head  of  the  flexor 
sublimis  digitorum,  the  flexor  profundus,  pronator  radii  teres,  and  occa- 
sionally the  flexor  longus  pollicis. 

The  shaft  or  body  tapers  from  above,  is  three-sided  in  its  upper  three- 
fourths,  slender  and  cylindrical  in  its  lower  fourth.  The  upper  three- 
fourths  are  convex  backward ;  it  is  also  convex  externally  above  and  in- 
ternally below.  The  anterior  border  passes  from  the  inner  edge  of  the 
coronoid  to  the  front  of  the  styloid  :  it  is  thick  and  rounded,  and  gives 
attachment  to  the  flexor  profundus  digitorum,  and  in  its  lower  fourth  to 
the  pronator  quadratus. 

The  posterior  border  begins  below  the  olecranon,  and  runs  with  a 
sinuous  curve  to  the  back  of  the  styloid.  It  is  ill  defined  below  and  sub- 
cutaneous throughout,  and  affords  attachment  to  an  aponeurosis  common 
to  three  muscles — the  flexor  carpi  ulnaris,  extensor  c.  ulnaris,  and  flexor 
profundus.  The  external  or  interosseous  border  is  a  sharp  edge  in  the 
middle  three-fifths  of  the  shaft.  ^  Below  it  is  faintly  marked.  The  upper 
one-fifth  is  continued  by  two  lines  passing  to  the  extremities  of  the  small 
sigmoid  notch :  the  posterior  line  is  prominent,  supinator  ridge^  for  the 
supinator  brevis  muscle. 

The  anterior  surface  is  concave  above,  and  gives  origin  to  the  flexor 
profundus  digitorum :  the  lower  one-third  is  marked  by  the  oblique  pro- 


THE   FOREARM.  71 

nator  ridge,  which  joins  the  anterior  border.  Above  the  middle  is  a 
medullary  foramen  directed  upward. 

The  internal  surface  is  smooth,  and  gives  attachment  to  the  flexor 
profundus  digitorum  muscle  :  it  is  subcutaneous  in  the  lower  one-third. 
The  posterior  surface  looks  outward  and  backward  :  an  oblique  line  de- 
scending from  the  supinator  ridge  to  the  posterior  border  at  the  junction 
of  its  upper  and  middle  thirds  marks  oiF  a  triangular  area  for  the  an- 
coneus muscle.  The  ridge  itself  gives  attachment  to  the  supinator 
brevis.  Below  this  is  a  longitudinal  ridge  dividing  the  surface  into  a 
smooth  inner  portion  covered  by  the  extensor  c.  ulnaris,  and  an  outer 
part  impressed  from  above  downward  by  the  extensor  ossis  metacarpi 
pollicis,  extensor  secundi  internod.  poll. ,  and  extensor  indicis. 

The  inferior  extremity  presents  a  rounded  head :  from  its  inner  and 
back  part  there  projects  downward  the  styloid  process,  giving  attachment 
to  the  internal  lateral  ligament  and  to  the  triangular  fibro-cartilage.  Be- 
tween the  head  and  styloid  process  is  a  groove  for  the  tendon  of  the  ex- 
tensor carpi  ulnaris. 

The  head  has  two  articular  surfaces — an  inferior  one,  upon  which  the 
triangular  fibro-cartilage  plays,  and  an  outer  narrow  convex  one,  for  the 
sigmoid  cavity  of  the  radius.  With  the  hand  supine  the  styloid  process 
projects  at  the  inner  and  back  part  of  the  wrist :  if  pronated,  the  outer 
and  fore  part  of  the  ulnar  head  is  prominent  between  the  tendons  of  the 
extensor  c.  ulnaris  and  extensor  min.  digiti. 

The  ulna  is  developed  from^  three  centres :  the  greater  part  of  the 
olecranon  grows  by  an  extension  from  the  shaft. 

Describe  the  radius. 

This  bone  articulates  with  the  humerus,  ulna,  scaphoid,  and  semilunar 
bones.  The  superior  extremity,  or  head  (eminentia  capitata),  is  disk- 
shaped.  On  its  summit  is  a  depression  for  the  capitellum  of  the  hume- 
rus. It  is  surrounded  by  a  convex  part,  broadest  internally,  which  rotates 
in  the  small  sigmoid  cavity  of  the  ulna  within  the  orbicular  ligament. 
The  head  is  supported  by  a  nech,  which  presents  behind  a  ridge  for  part 
of  the  insertion  of  the  supinator  brevis. 

The  shaft  is  larger  below  than  above,  slightly  curved,  and  convex  out- 
ward and  backward.  Antero-internally  below  the  neck  is  the  bicipital 
tuberosity,  rough  posteriorly  for  the  insertion  of  the  biceps,  and  smooth 
in  front  for  a  bursa.  Below  this  tuberosity  the  shaft  has  three  surfaces 
and  three  borders. 

The  anterior  border  extends  from  the  tuberosity  to  the  base  of  the 
styloid :  its  upper  part  is  called  the  anterior  oblique  line,  and  gives  at- 
tachment to  the  supinator  brevis,  flexor  longus  poUicis,  pronator  radii 
teres,  and  flexor  sublimis. 

The  posterior  border  runs  from  the  back  of  the  neck  to  the  posterior 
part  of  the  base  of  the  styloid.  It  is  well  marked  only  in  its  middle 
third. 

The  internal  or  interosseous  border  becomes  prominent  below,  and  at 


^2  BONES  OF  THE  UPPER  EXTREMITY. 

its  lower  part  divides  into  two  ridges  which  meet  the  margins  of  the 
sigmoid  cavity,  analogous  to  the  division  of  a  like  border  of  the  ulna. 

The  anterior  surface  is  grooved  longitudinall}^  for  the  flexor  long.  poll, 
muscle:  at  the  lower  end  is  a  flattened  impression  for  the  pronator 
quadratus,  which  also  rises  from  a  small  surface  at  the  inner  side  of  the 
bone.     A  medullary  foramen  is  above  the  middle  of  this  surface. 

The  posterior  surface  shows  at  the  junction  of  the  upper  and  middle 
thirds  the  posterior  oblique  line,  below  which  is  attached  the  extensor 
ossis  metacarpi  poll.,  and  below  that  the  extensor  primi  internodii 
poll.  The  external  surface  is  convex,  and  marked  near  the  middle  by 
an  impression  for  the  pronator  radii  teres :  above  this,  on  the  area  be- 
tween the  anterior  and  posterior  oblique  lines,  is  inserted  the  supinator 
brevis. 

The  lower  extremity  of  the  radius,  broad  and  quadrilateral,  presents  a 
carpal  articular  surface  and  an  ulnar  articular  surface.  The  former  is 
divided  by  a  line  into  a  quadrilateral  inner  part  for  the  semilunar, 
and  a  triangular  outer  part  for  the  scaphoid.  The  articular  surface 
for  the  ulna  or  sigmoid  cavity  is  at  right  angles  to  the  inferior  surface, 
and  concave  from  before  backward.  To  the  smooth  border  between 
these  two  articular  surfaces  is  attached  the  base  of  the  triangular  fibro- 
cartilage.  Externally  the  styloid  process  projects  downward.  Ante- 
riorly a  transverse  ridge  forms  the  lowest  limit  of  the  pronator  quad- 
ratus impression,  which  is  continued  into  a  vertical  ridge  external  to 
that  impression:  between  this  ridge  and  the  scaphoid  facet  is  a  tri- 
angular area  for  a  strong  band  of  the  anterior  ligament.  The  ex- 
ternal and  posterior  aspects  are  marked  by  the  following  grooves  from 
without  inward :  a  flat  groove  for  the  extensor  ossis  met.  poll,  and  ex- 
tensor prim,  internod.  (next  descends  the  styloid  process) ;  a  broad 
groove,  subdivided  by  a  slight  ridge,  for  the  extensor  carpi  rad.  longior 
and  brevior ;  an  oblique  narrow  groove,  bounded  externally  by  a  tubercle, 
for  the  extensor  secundi  internod.  poll.  ;  a  broad  groove  for  the  extensor 
indicis,  extensor  communis,  and  extensor  min.  dig.  Just  above  the  first 
groove  is  an  impression  for  the  supinator  longus. 

The  relative  length  of  the  forearm  to  the  arm  is  expressed  by  the  humero- 
radial index :  Eskimo,  71  (i  e.  the  radius  is  71  if  the  humerus  be  taken  as 
100);  European,  74;  gorilla,  80;  orang,  100.  The  index  is  higher  in  the  foetus 
and  infant.  The  radius  in  bats  and  birds  is  very  long  and  supports  the  wing. 
The  radius  is  developed  from  three  centres.  All  the  epiphyses  around  the 
elbow  unite  earlier  than  those  at  the  opposite  ends  of  the  bones. 

THE  HAND. 

The  skeleton  of  the  hand  consists  of  three  segments — wrist-bones, 
bones  of  palm,  and  bones  of  fingers. 

Describe  the  carpus,  or  wrist-bones. 

The  carpus  is  composed  of  eight  short  bones  arranged  in  two  rows : 
the  upper  row,  from  radial  to  ulnar  side,  comprises  the  scaphoid,  lunar 


THE   HAND.  73 

(semilunar),  pyramidal  (cuneiform),  and  pisiform;  in  the  inferior  row 
are  the  trapezium,  trapezoid,  os  magnum,  and  unciform.  The  dorsal 
surface  of  the  carpus  is  convex,  and  palmar  concave  transversely ;  the 
concavity  is  bounded  by  four  prominences  (eminentiae  carpi),  one  at  each 
end  of  each  row,  to  which  the  anterior  annular  ligament  is  attached. 
The  superior  surfaces  of  the  scaphoid,  lunar,  and  pyramidal  form  a  me- 
niscus for  articulation  with  the  concavity  presented  by  the  radius  and 
triangular  fibro-cartilage.  The  mid-carpal  articulation  is  concavo-con- 
vex, the  trapezium,  trapezoid,  and  os  magnum  forming  a  concavity 
for  the  scaphoid,  while  the  unciform  and  head  of  the  os  magnum  rise 
up  in  a  convexity.  Each  bone  is  more  or  less  cubical  and  presents  six 
surfaces. 

The  scaphoid  (boat-like)  has  its  long  axis  directed  down  and  out. 
Internally  it  has  two  articular  facets,  a  lower  one  for  the  os  magnum  and 
an  upper  crescentic  one  for  the  lunar.  The  superior  surface  is  smooth 
and  triangular,  passes  farther  back  than  forward,  and  articulates  with 
the  radius.  The  inferior  surface  is  smooth  and  convex,  divided  by  a 
ridge,  articulating  externally  with  the  trapezium  and  internally  with  the 
trapezoid.  The  anterior  surface  is  concave  above,  and  presents  a  conical 
tuberosity  below.  The  external  surface  is  rough  and  narrow.  The  pos- 
terior surface  is  a  narrow  transverse  groove. 

The  lunar  bone  is  characterized  by  a  deep  concavity  from  before  back- 
ward on  its  inferior  surface ;  it  is  for  the  head  of  the  os  magnum.  This 
surface  also  presents  a  long  narrow  facet  for  the  unciform.  Externally 
it  is  crescentic  and  vertical  for  the  scaphoid.  Its  internal  surface  looks 
down  and  in,  is  narrower  than  the  external,  and  articulates  with  the 
pyramidal.  The  convex  upper  surface  is  four-sided,  articulates  with 
the  radius,  and  extends  farther  back  than  forward,  so  that  the  anterior 
free  surface  is  deeper  than  the  posterior. 

The  pyramidal  (cuneiform)  bone  directs  its  blunted  apex  down  and 
in.  The  base  shows  a  flat  quadrilateral  surface  for  the  lunar.  The  in- 
ferior surface  is  concavo-convex  from  without  inward,  and  articulates 
with  the  unciform.  The  anterior  surface  has  a  small  articular  facet  on 
its  inner  half  for  the  pisiform.  The  supero-posterior  surface  has  near 
the  base  an  articular  facet  for  the  triangular  fibro-cartilage,  but  is  mostly 
rough  for  ligaments. 

The  pisiform  (like  a  pea)  is  anterior  to  the  other  bones  of  the  carpus. 
It  is  spheroidal,  with  longest  diameter  directed  vertically.  Posteriorly  is 
is  an  oval  facet  for  the  pyramidal,  leaving  a  free  portion  below.  The 
inner  surface  is  convex  and  rough  ;  the  outer,  toward  the  flexor  tendons, 
is  smoother  and  slightly  concave. 

The  trapezium  (a  table)  is  the  most  external  of  the  second  row.  The 
supero-internal  surface  is  concave  and  ^articulates  with  the  scaphoid. 
The  inferior  surface,  directed  down  and  *out,  is  concavo-convex  for  the 
first  metacarpal,  The  internal  surface  articulates  with  the  trapezoid, 
and  on  its  lower  inner  angle  with  the  second  metacarpal.  The  anterior 
surface  is  marked  by  a  vertical  groove  for  the  flexor  carpi  radialis  tendon, 


74 


BONES  OF  THE  UPPER  EXTREMITY. 


external  to  which  is  a  ridge  or  tuberosity  for  the  annular  ligament.  The 
anterior,  external,  and  dorsal  surfaces  are  free. 

The  trapezoid  is  much  smaller  than  the  trapezium  ;  its  longest  diam- 
eter is  from  before  backward,  and  its  posterior  surface  is  larger  than  its 
anterior.  The  external  inferior  angle  of  the  anterior  surface  is  pro- 
longed backward  between  the  smooth  surface  for  the  trapezium  and  that 
for  the  second  metacarpal  bone.  The  superior  surface  is  quadrilateral 
and  articulates  with  the  scaphoid ;  the  external  is  convex  for  the  tra- 
pezium ;  the  internal  articulates  with  the  os  magnum ;  and  the  inferior 
concavo-convex  surface  with  the  second  metacarpal.  Hold  the  bone 
with  the  larger  non-articular  surface  toward  j^ou  and  the  smooth  quadri- 
lateral articular  surface  upward  (for  scaphoid) ;  the  convex  articular  sur- 
face (for  the  trapezium)  will  point  to  the  side  to  which  the  bone  belongs. 

The  OS  magnum  (os  capitatum)  is  the  largest  of  the  carpal  bones,  rec- 
tangular below  and  rounded  above.  The  upper  extremity,  or  head^  ar- 
ticulates with  the  lunar,  its  smooth  surface  extending  farther  behind  than 
in  front,  and  prolonged  upon  its  outer  side  for  the  scaphoid.  The  nech 
is  formed  by  depressions  anteriorly  and  posteriorly.  The  anterior  surface 
is  narrower  than  the  posterior.  The  posterior  surface  projects  down- 
ward at  its  internal  inferior  angle.  Externally,  below  the  surface  for  the 
scaphoid,  is  a  facet  for  the  trapezoid.  On  the  posterior  part  of  the  in- 
ner surface  is  a  vertical  facet  for  the  unciform.  Inferiorly  there  are  three 
facets,  the  middle  being  the  larger,  for  the  second,  third,  and  fourth 
metacarpal  bones. 

The  unciform  (hook-hke)  bone  is  wedge-shaped,  with  its  base  or  infe- 
rior surface  resting  on  the  fourth  and  fifth  metacarpal  bones :  its  apex 
points  up  and  out  and  articulates  with  the  lunar.  The  external  surface 
is  vertical,  and  articulates  with  the  os  magnum  by  its  upper  posterior 
part.  Its  supero-internal  surface  is  concavo-convex  for  the  pyramidal : 
it  is  separated  from  the  inferior  surface  by  a  rough  border.  The  anterior 
surface  at  its  lower  and  inner  side  presents  the  unciform  process^  pro- 
jecting forward  and  curved  slightly  outward. 


ARTICULATIONS   OF   CARPAL  BONES. 


Scaphoid  .  . 

Lunar  .  .   . 

Pyramidal  . 

Pisiform 
Trapezium  . 

Trapezoid.  . 
Os  magnum 

Unciform.  . 


Superior.      External. 


radius 

radius 

triangular 
fib.  cart, 
free 
scaphoid 

scaphoid 
scaphoid 

lunar 
lunar 


free 

scaphoid 

lunar 

free 
free 

trapezium 
trapezoid 

OS  magnum 


Inferior. 


trapezium 
trapezoid 

08  magnum 
unciform 

unciform 

free 

1st  metacarp. 

2d  metacarp. 
2d,3d,  and  4th 

metacarp. 
3d     and    4th 

metacarp.   | 


Internal. 


OS  magnum 

lunar 
pyramidal 

free 


Ante- 
rior. 


free 
free 


pisi- 
form 
free 
free 


free 

trapezoid 

2d  metacarp 

OS  magnum    free 

unciform        free 


pyramidal 


free 


Posterior. 


free 

free 

free 

pyramidal 
free 

free 
free 

free 


Num- 
ber. 

5 
5 


THE   HAND.  75' 

The  carpus  is  wholly  cartilaginous  at  birth  :  each  bone  is  developed  from  a 
single  centre  except  the  scaphoid.  The  nucleus  of  the  pisiform  does  not  ap- 
pear till  the  twelfth  year,  the  latest  of  all  primary  centres.  In  the  foetus  the 
scaphoid  has  normally  a  second  cartilaginous  element,  which  may  develop 
into  the  os  centrale  placed  on  the  back  of  the  carpus  between  the  scaphoid,  os 
magnum,  and  trapezoid.  The  styloid  process  of  the  third  metacarpal  may  be 
separated  as  a  supernumerary  bone. 

Describe  the  metacarpus,  or  bones  of  palm. 

The  metacarpus  supports  the  fingers  and  consists  of  five  long,  sHghtly 
divergent  bones.  They  form  the  segment  of  a  transverse  arch :  their 
carpal  extremities  are  expanded  bases  and  their  digital  ends  are  rounded 
heads.  The  first  metacarpal  is  broad  and  short,  the  second  longest  of 
all,  while  the  third,  fourth,  and  fifth  decrease  regularly  in  length.  The 
shafts  are  curved  longitudinally,  and  are  three-sided,  presenting  a  pos- 
terior surface  and  anteriorly  a  median  margin  between  two  lateral  sur- 
faces. They  are  more  slender  near  the  carpal  ends  and  thicker  toward 
the  heads.  The  dorsal  surface  is  triangular,  being  bounded  by  lines 
which  proceed  from  the  sides  of  the  head  and  converge  in  the  second, 
third,  and  fourth  metacarpals  opposite  the  middle  of  the  carpal  extremity. 
The  heads  articulate  with  the  proximal  phalanges :  their  smooth  surfaces 
broaden  and  extend  farther  on  the  palmar  than  on  the  dorsal  aspect. 
On  each  side  is  a  tubercle,  with  a  hollow  below  it  for  attachment  of  the 
lateral  ligament.  The  carpal  extremities  present  distinctions.  The  first 
bone  has  a  saddle-shaped  articular  surface,  and  externally  a  prominence 
for  the  insertion  of  the  extensor  ossis  metacarpi  poll.  The  shaft  is  com- 
pressed and  dorsal  surface  convex.  On  the  palmar  surface  the  rounded 
ridge  is  nearer  the  inner  than  the  outer  border.  The  carpal  extremity 
of  the  second  is  notched  for  the  trapezoid.  On  the  radial  side  is  a  facet 
for  the  trapezium,  and  close  to  it  an  impression  for  the  extensor  carp, 
rad.  long.  A  prominent  ulnar  lip  with  two  long  facets  is  the  distinguish- 
ing feature.  The  third  bone  presents  a  styloid  process  on  the  posterior 
radial  angle,  passing  up  behind  the  os  magnum,  and  below  it  an  impres- 
sion for  the  extensor  carp.  rad.  brev.  The  radial  side  has  one  facet  and 
the  ulnar  side  two.  The  carpal  extremity  of  the  fourth  has  two  facets 
on  the  radial  side,  and  a  concave  semielliptical  one  on  the  ulnar  side. 
The  fifth  has  a  saddle-shaped  surface  for  the  unciform,  and  a  tuberosity 
on  the  ulnar  side  for  the  extensor  carpi  ulnaris.  There  is  only  one  oblique 
ridge  on  the  dorsal  surface,  extending  from  the  radial  side  of  the  head 
to  the  ulnar  side  of  the  base. 

The  first  metacarpal  articulates  at  its  base  with  1  bone. 

The  second  metacarpal  articulates  at  its  base  with  4  bones. 

The  third  metacarpal  articulates  at  its  base  with  3  bones. 

The  fourth  metacarpal  articulates  at  its  base  with  4  bones. 

The  fifth  metacarpal  articulates  at  its  base  with  2  bones. 

It  is  interesting  that  the  corresponding  metatarsals  articulate  with  ex- 
actly the  same  number. 


76  BONES   OF   THE   LOWER   EXTREMITY. 

Describe  the  digital  phalanges. 

The  phalanges  (internodia)  are  fourteen  in  number,  three  for  each 
finger  and  two  for  the  thumb.  Those  of  the  first  row,  five  in  number, 
are  sHghtly  curved.  The  dorsal  surface  is  transverse!}^  convex,  while 
the  palmar  is  flat  and  bounded  by  rough  margins.  Their  metacarpal 
extremities  are  thick  and  present  a  transversely  concave  surface ;  their 
distal  extremities  are  smaller  and  divided  by  a  median  groove  into  two 
condyles.  The  bones  of  the  middle  roiv  are  four  in  number,  and  smaller 
than  the  preceding:  their  proximal  articular  surfaces  show  a  middle 
ridge  and  two  lateral  depressions.  The  distal  ends  are  like  those  of  the 
first  row.  The  terminal  or  ungual  phalanges  are  five  in  number:  their 
proximal  extremities  are  like  those  of  the  middle,  but  with  a  depression 
in  front  for  the  deep  flexor.  Their  free  extremities  are  flat  and  expanded, 
and  raised  round  the  margins  of  the  palmar  aspect  into  an  ungual  process. 

Where  are  the  sesamoid  bones  of  the  hand? 

One  pair,  each  i  inch  (5  mm.)  in  diameter,  is  placed  in  the  palmar 
wall  of  the  metacarpo-phalangeal  joint  of  the  thumb ;  others,  single  or 
double,  may  occur  in  the  corresponding  joint  of  the  index  and  little 
fingers,  more  rarely  in  the  third  and  fourth. 

Collectively,  the  phalanges  of  the  middle  finger  are  longest,  then  those  of 
the  ring,  index,  little  finger,  and  thumb.  In  some  hands  the  index  is  longer 
than  the  ring,  due  wholly  to  the  length  of  the  metacarpal  bone. 

The  metacarpals  and  phalanges  are  formed  each  from  one  centre  for  the 
shaft,  and  one  for  an  epiphysis.  In  the  four  inner  metacarpals  the  epiphyses 
are  at  the  heads ;  in  the  metacarpal  of  the  thumb  and  in  the  phalanges  the 
epiphyses  are  at  the  bases.  The  so-called  first  metacarpal  therefore  resembles 
a  phalanx.  The  ungual  phalanges  are  peculiar  in  beginning  to  ossify  at  the 
distal  extremities  instead  of  in  the  middle.  In  the  metacarpals  the  medul- 
lary foramen  is  on  the  radial  side  of  the  palmar  surface,  and  the  canal  runs 
toward  the  base ;  in  the  phalanges  and  first  metacarpal  the  canal  runs  toward 
the  head  of  the  bone. 

BONES  OP  THE  LOWER  EXTREMITY. 

The  lower  limb  consists  of  the  haunch  or  hip,  thigh,  leg,  and  foot. 
In  the  haunch  is  the  hip-bone,  in  the  thigh  the  femur,  in  the  leg  the 
tibia  and  fibula,  at  the  knee  a  large  sesamoid  bone,  the  patella,  in  the 
foot  the  tarsus,  metatarsus,  and  phalanges.  The  pelvis  and  hip-bone 
are  a  part  of  the  lower  extremity. 

THE  PELVIS. 

Describe  the  hip-bone. 

The  hip  or  innominate  bone  (os  coxae),  with  its  fellow,  the  sacrum, 
and  coccyx  form  the  pelvis.  This  bone  is  constricted  in  the  middle  and 
expanded  above  and  below ;  it  has  been  likened  to  the  shape  of  a  meat- 
chopper. 


THE   PELVIS.  77 

The  acetabulum  is  on  the  outer  aspect  of  the  constricted  portion,  and 
the  inferior  expanded  portion  is  perforated  by  the  thyroid  or  obturator 
foramen.  The  bone  above  forms  part  of  the  abdominal  wall,  and  below 
part  of  the  true  pelvis.  In  early  life  the  ilium^  pubes,  and  ischium  are 
distinct. 

The  ilium  [ilia^  flanks;  ileum  is  a  part  of  the  small  intestine)  is  the  su- 
perior expanded  portion,  and  forms  less  than  two-fifths  of  the  acetab- 
ulum. This  portion  is  limited  anteriorly  and  posteriorly  by  margins 
which  diverge  at  right  angles  from  each  other,  and  superiorly  by  the 
arched  crest  of  the  ilium.  In  front  the  crest  is  concave  inward  and  behind 
it  is  concave  outward  :  there  is  a  marked  external  projection  in  the  ante- 
rior third.  On  the  crest  are  external  and  internal  lips  and  a  median 
ridge.  The  anterior  extremity  projects  as  the  anterior  superior  spine; 
below  it  is  a  concavity,  the  lesser  iliac  notch.,  and  below  that  the  anterior 
inferior  spine.  Behind,  the  projecting  extremity  of  the  crest  is  called 
the  posterior  superior  spine^  sej)arated  by  a  small  notch  from  the  poste- 
rior inferior  spine.,  below  which  is  the  great  sciatic  (ilio-sciatic)  notch. 

The  external  surface  or  dorsum  ilii  presents  three  curved  gluteal  lines. 
The  posterior  or  superior  one  commences  2  inches  in  front  of  the  poste- 
rior superior  spine,  and  curves  down  and  forward  to  the  back  part  of  the 
ilio-sciatic  notch.  The  middle  gluteal  line  begins  in  front  about  1 J  inches 
behind  the  anterior  superior  spine,  and  arches  back  and  down  to  the 
upper  part  of  the  notch.  The  inferior  gluteal  line,  less  strongly  marked, 
commences  just  above  the  anterior  inferior  spine,  and  passes  back  to  the 
fore  part  of  the  notch.  Behind  the  posterior  line  is  a  semilunar  surface, 
rough  above  for  the  gluteus  maximus  :  the  sickle-shaped  space  between 
the  posterior  and  middle  lines  and  iliac  crest  is  occupied  by  the  gluteus 
medius ;  the  gluteus  minimus  is  between  the  middle  and  inferior  lines. 
Just  above  the  acetabulum  is  an  elongated  mark  for  the  reflected  head 
of  the  rectus  femoris. 

The  internal  surface  is  divided  into  two  parts :  the  anterior  part  is 
the  iliac  fossa  or  venter  ilii.  To  the  inner  side  of  the  anterior  inferior 
spine  is  a  shallow  groove,  the  greater  iliac  notch,  which  lodges  the  ilio- 
psoas muscle :  the  inner  boundary  of  the  groove  is  the  ilio-pectineal  emi- 
nence, marking  the  junction  of  the  pubis  and  ilium.  The  posterior  part 
(sacral  surface)  h  again  divided,  presenting  from  below  upward  (1)  a 
smooth  surface  in  the  true  pelvis,  separated  from  the  iliac  fossa  by  the 
iliac  portion  of  the  ilio-pectineal  line  ;  (2)  the  auricular  surface,  for  articu- 
lation with  the  sacrum;  (3)  depressions  on  the  iliac  tuberosity,  for  the 
posterior  sacro-iliac  ligament ;  (4)  a  rough  surface  giving  origin  to  the 
erector  and  multifidus  spinae  muscles. 

The  iliac  crest  gives  attachment  by  its  outer  lip  to  the  tensor  vaginae  fem- 
oris, obliquus  externus,  latissimus  dorsi,  and  fascia  lata;  by  its  middle  ridge 
to  the  obliquus  internus ;  by  its  inner  lip  to  the  transversalis,  quadratus  lum- 
])orum,  erector  spina?,  and  iliac  fascia.  To  the  anterior  superior  spine  is  attached 
externally  the  tensor  vaginse  femoris,  in  front  the  sartorius,  and  internally 
Poupart's  ligament.     From  the  anterior  inferior  spine  originates  the  straight 


78  BONES   OF   THE   LOWER   EXTREMITY. 

head  of  the  rectus  :  just  below  this  is  an  impression  for  the  ilio-femoral  liga- 
ment. The  iliac  part  of  the  ilio-pectineal  line  gives  attachment  to  the  iliac 
and  obturator  fasciae  and  tendon  of  the  psoas  parvus. 

The  OS  pubis  forms  the  anterior  wall  of  the  pelvis,  and  bounds  the 
thyroid  foramen  above.  It  forms  about  one-fifth  of  the  acetabulum  :  at 
its  inner  extremity  is  a  long  oval  surface  marked  by  transverse  ridges  or 
nipple-like  processes  for  articulation  with  the  opposite  bone  ;  the  junc- 
tion is  the  symphysis  pubis.  The  part  passing  down  and  out  from  the 
symphysis  is  the  descending  ramus ;  the  upper  part  is  the  superior  or 
ascending  ramus ;  and  the  flat  portion  between  the  rami  is  the  body. 
The  pelvic  surface  of  the  body  is  smooth,  the'  anterior  surface  rough. 
The  upper  extremity  of  the  symphysis  is  the  angle;  extending  out  from 
this  on  the  superior  border  is  the  crest,,  terminating  in  the  spane.  The 
descending  ramus  is  thin  and  flat,  and  joins  that  of  the  ischium  at  the 
pubo-ischiatic  tuberosity.  The  superior  ramus  becomes  prismatic :  its 
superior  border  is  the  pubic  portion  of  the  ilio-pectineal  line^  running  from 
the  spine  of  the  pubis  to  the  ilio-pectineal  eminence.  The  triangular 
surface  in  front  of  this  line  gives  origin  to  the  pectineus  muscle  :  below 
is  the  obturator  crest,  extending  from  the  pubic  spine  to  the  margin  of 
the  acetabulum.  Behind  the  outer  part  of  the  crest  on  the  inferior  sur- 
face of  the  ramus  is  the  obturator  groove^  directed  from  behind  forward 
and  inward  :  it  is  limited  by  the //(/enbr  and  superior  obturator  tubercles. 

The  pubic  crest  gives  origin  to  part  of  the  conjoined  tendon,  the  pyramidalis 
and  rectus  abdominis.  To  the  pubic  spine  is  inserted  Poupart's  ligament  and 
the  outer  pillar  of  the  external  abdominal  ring.  From  the  front  of  the  pubis, 
in  the  angle  between  the  crest  and  symphysis,  rises  the  adductor  longus  mus- 
cle, and  below  this  the  adductor  brevis  and  part  of  the  adductor  magnus. 
Internal  to  these  the  gracilis  is  attached,  and  external  the  obturator  externus. 
Posteriorly  the  pubis  gives  attachment  to  the  obturator  internus  :  above  this 
is  sometimes  a  faint  line  passing  from  the  upper  margin  of  the  obturator  for- 
amen to  the  lower  end  of  the  symphysis ;  the  levator  ani  muscle  is  attached  to 
it,  and  the  obturator  and  recto- vesical  fasciae. 

The  ischium  forms  the  lower  and  back  part  of  the  hip-bone,  bounds 
the  thyroid  foramen  below,  and  forms  over  two-fifths  of  the  acetabulum. 
It  presents  a  body,  and  below  this  a  tuberosity  continued  forward  into  the 
ramus.  The  body  has  three  surfaces,  external,  internal,  and  posterior. 
The  external  surface  helps  form  the  acetabulum  ;  below  this  and  above 
the  tuberosity  is  a  horizontal  groove  for  the  tendon  of  the,obturator  ex- 
ternus muscle.  The  internal  surface  is  smooth,  and  forms  part  of  the 
wall  of  the  true  pelvis.  In  front  it  is  separated  from  the  iliac  fossa  by 
the  iliac  portion  of  the  ilio-pect.  line,  but  behind  the  junction  of  the 
ischuim  and  ilium  does  not  reach  that  line.  The  posterior  surface  is 
quadrilateral,  getting  narrow  below,  and  continuous  with  the  tuberosity. 
It  presents  a  part  of  the  groove  for  the  obturator  externus,  and  sup- 
ports the  pyriformis,  the  two  gemelli,  and  the  obturator  internus. 

On  the  posterior  border  is  the  spine,  projecting  back  and  in,  and  form- 
ing the  inferior  limit  of  the  Uio-sciatic  notch. 


THE   PELVIS.  79 

The  small  sciatic  notch  is  between  the  spine  and  tuberosity.  The 
tuberosity  presents  two  lips  and  an  intermediate  space.  The  external  lip 
gives  attachment  to  the  quadratus  femoris  and  adductor  magnus ;  the 
inner  Hp  to  the  falciform  portion  of  the  great  sacro-sciatic  Hgament,  and 
more  anteriorly  to  the  transversus  perinei  and  erector  penis.  The  inter- 
mediate space  is  divided  into  two  portions :  the  anterior  part  attaches 
the  adductor  magnus  externally  and  great  sacro-sciatic  hgament  in- 
ternally ;  the  posterior  part  has  two  facets,  an  upper  and  outer  for  the 
semimembranosus,  a  lower  and  inner  for  the  biceps  and  semitendinosus. 

The  ramus  joins  the  descending  ramus  of  the  pubis  at  the  inner  side 
of  the  thyroid  foramen.  Its  outer  surface  gives  attachment  to  the  obtu- 
rator externus,  adductor  magnus,  and  gracilis.  The  crus  penis,  and 
above  that  the  constrictor  urethrae,  are  attached  to  the  inner  border. 

The  acetabulum,  or  cotyloid  cavity,  is  cup-shaped,  and  looks  out, 
down,  and  forward.  It  is  nearly  surrounded  by  a  prominent  rim  which 
presents  three  depressions — a  slight  one  anteriorly  and  posteriorly,  and 
the  cotyloid  notch  below.  In  the  lateral  and  upper  parts  of  the  cavity 
is  a  broad  horseshoe-shaped  articular  surface.  From  the  anterior  corner 
of  the  horseshoe  run  two  lines,  one  up  and  forward  as  the  obturator 
crest  to  the  pubic  spine,  the  other  backward  to  the  superior  obturator 
tubercle.  The^  central  part  of  the  cup  and  the  notch  are  depressed 
(fossa  acetabuli),  and  contain  fat  and  the  interarticular  ligament.  This 
non-articular  surface  belongs  mostly  to  the  ischium. 

The  thyroid  or  obturator  foramen  (foramen  ovale)  is  internal  to  and 
below  the  acetabulum.  It  is  nearly  oval  in  the  male,  more  triangular  in 
the  female.  It  is  closed  by  fibrous  membranes,  except  in  the  region  of 
the  obturator  groove  in  its  upper  margin. 

The  hip-bone  is  strongest  along  lines  of  greatest  pressure.  There  is  a  thick 
bar  on  the  ilium  from  the  auricular  surface  to  the  acetabulum,  also  a  second 
in  the  ischium  and  its  tuberosity,  and  another  running  up  from  the  acetabulum 
to  the  most  prominent  part  of  the  crest.  The  iliac  fossa  and  floor  of  the  ace- 
tabulum are  very  thin  :  vascular  foramina  perforate  the  thickest  parts  of  the 
bone.  There  may  be  an  accessory  ischial  spine  in  the  great  sacro-sciatic 
notch.  The  pelves  of  most  Javanese  women  present  a  preauricular  sulcus  for 
the  anterior  sacro-iliac  ligament,  rarely  developed  in  European  women. 

The  OS  innominatum  is  developed  from  eight  or  more  centres  in  three  prin- 
cipal pieces.  By  the  seventh  or  eighth  year  the  three  pieces  are  separated  by 
a  Y-shaped  cartilage  in  the  acetabulum,  which  begins  to  ossify  by  the  twelfth 
year  from  several  centres :  the  most  constant  gives  rise  to  a  triangular  os  ace- 
tabuli, which  forms  the  whole  of  the  pubic  portion  of  the  articular  cavity. 
Between  the  ilium  and  ischium  are  some  irregular  nodules,  and  a  lamina 
spreads  over  the  iliac  and  ischial  portions  of  the  articular  surface.  Secondary 
centres  appear  for  the  crest  of  the  ilium,  the  tuber  ischii,  the  anterior  inferior 
spine,  and  symphysis:  all  are  joined  to  the  main  bone  by  the  twenty-fifth 
year. 

Describe  the  pelvis  as  a  whole. 

The  pelvis  (basin)  is  composed  of  four  bones — two  ossa  innominata, 
the  sacrum,  and  coccyx.     It  is  divided  into  two  parts  by  a  plane  passing 


80  BONES   OF   THE   LOWER   EXTREMITY. 

through  the  sacral  promontory,  ilio-pectineal  lines,  and  upper  border  of 
symphysis.  This  circle  is  the  inlet  or  brim  of  the  true  pelvis :  the  space 
above  it  really  belongs  to  the  abdomen,  but  is  called  the  false  or  upper 
pelvis.  The  pelvic  outlet  presents  three  large  prominences,  the  coccyx 
and  tuberosities  of  the  ischia.  Beneath  the  symphysis  and  between  the 
ischial  tuberosities  is  the  subpubic  arch ;  behind  the  tuberosities  are  the 
sacro-sciatic  notches. 

What  is  the  position  of  the  pelvis  ? 

In  the  erect  attitude,  with  the  heels  together  and  toes  turned  out,  the 
plane  of  the  brim  forms  60°  with  the  horizontal,  that  of  the  outlet  16°. 
The  base  of  the  sacrum  is  about  3  J  inches  above  the  upper  margin  of 
the  symphysis,  and  the  tip  of  the  coccyx  about  i  inch  above  the  apex 
of  the  subpupic  arch.  The  sacrum  looks  down  and  forward,  and  is  the 
inverted  keystone  of  an  arch,  as  its  pelvic  surface  is  broader  than  the 
dorsal :  it  is  held  in  place  chiefly  by  ligaments  and  by  a  slight  bony  pro- 
jection into  the  iliac  articular  surface  (Fig.  12). 

What  are  the  differences  according  to  sex? 

In  the  female  the  bones  are  more  slender  and  muscular  impressions 
less  marked  ;  the  height  is  less,  breadth  and  capacity  greater ;  but  the 
false  pelvis  is  relatively  narrower  than  in  the  male.  The  sacrum  is  wider 
and  flatter,  less  prominent,  the  subpubic  arch  is  wider,  about  90°  (male 
is  75°),  and  the  space  between  the  ischial  tuberosities  is  greater.  The 
thyroid  foramen  is  broader  and  more  triangular  in  the  female,  nearly 
oval  in  the  male. 

The  characteristics  of  the  human  pelvis  compared  with  that  of  lower  ani- 
mals are  its  shallowness  and  breadth,  great  capacity  of  true  pelvis,  expansion 
of  ilia,  straightness  of  ischial  tuberosities,  and  shortness  of  symphysis.  The 
pelvis  of  the  kangaroo  is  so  small  that  the  young  are  born  when  li  inches 
long,  and  placed  in  a  pouch  on  the  abdomen  of  the  mother,  with  the  nipple 
firmly  fixed  in  their  mouths. 

THE  SACRUM  AND  COCCYX.     (See  FalseVertdjrce,  p.  28.) 

THE  THIGH. 
Describe  the  femur. 

The  femur  (thigh-bone)  is  the  largest,  longest,  and  strongest  bone  of 
the  skeleton.  In  the  erect  position  it  inclines  inward  and  shghtly  back- 
ward. It  is  divisible  into  a  superior  extremity^  including  head^  nech^  and 
two  trochanters;  shaft;  and  inferior  extremity^  expanded  into  external 
and  internal  condyles  and  epicondyles. 

The  nech  extends  upward,  inward,  and  slightly  forward,  being  set  upon 
the  shaft  at  an  angle  of  125°.  It  is  compressed  from  before  backward, 
is  broad  at  its  base,  becomes  rounded  at  its  summit,  and  enlarged  as  it 
joins  the  head.  It  is  shorter  above  and  in  front  than  below  and  behind. 
Posteriorly  it  usually  shows  a  shallow  groove  for  the  obturator  externus 


THE   THIGH.  81 

tendon.  Reasons  for  a  neck  are — ( 1)  to  transmit  shock  through  an  arch ; 
(2)  room  for  adductor  muscles ;  (3)  room  for  pelvic  muscles  to  femur. 

The  head  forms  more  than  half  a  sphere :  its  posterior  inferior  quad- 
rant shows  a  depression  (fossa  capitis),  the  fore  part  of  which  gives 
attachment  to  the  interarticular  hgament  (lig.  teres)  of  the  joint.  In 
this  hollow  are  one  or  two  vascular  foramina. 

The  great  trochanter  (to  turn)  is  a  thick  process  prolonged  upward  in 
a  line  with  the  external  surface  of  the  shaft  to  a  level  about  i  or  f  inch 
below  the  head.  In  front  it  is  marked  by  a  broad  depression  for  the 
'gluteus  minimus.  Externally  an  oblique  line  runs  downward  and  for- 
ward, indicating  the  inferior  border  of  the  gluteus  medius  insertion. 
Lower  down  is  a  horizontal  line  continued  to  the  tubercle  of  the  femur ^ 
which  is  situated  in  front  at  the  junction  of  the  neck  with  the  tuberosity : 
the  tubercle  is  the  meeting- place  of  five  muscles — vastus  externus,  gluteus 
minimus,  obturator  internus,  and  two  gemelli.  Internally,  at  the  base 
of  the  trochanter  and  rather  behind  the  neck,  is  the  digital  fossa,  giving 
attachment  to  the  obturator  externus  tendon.  Above  and  in  front  of 
this  is  the  insertion  of  the  obturator  internus  and  gemelU  muscles. 

The  upper  border  of  the  trochanter  is  narrow,  and  presents  an  oval 
inark  for  the  pyriformis.  The  posterior  border  is  prominent,  and  con- 
tinuous with  the  posterior  lutertrochanteric  line,  limiting  the  neck  poste- 
riorly. Above  the  centre  of  this  line  is  the  tubercle  o/  the  quadratus, 
for  attachment  of  the  upper  part  of  the  quadratus  femoris:  sometimes 
a  Itnea  quadrati  passes  vertically  down  from  the  tubercle. 

The  small  trochanter  is  a  pyramidal  eminence  projecting  from  the 
postero-internal  aspect  of  the  bone  at  the  junction  of  the  neck  with  the 
shaft.     Its  apex  gives  attachment  to  the  ilio-psoas  tendon. 

Anteriorly  the  neck  of  the  femur  is  separated  from  the  shaft  by  the 
anterior  intertrochanteric  line,  which  is  the  upper  part  of  the  spiral  line 
(does  not  connect  the  trochanters) :  it  commences  at  the  tubercle  of  the 
femur,  and  runs  down  and  in  a  finger's  breadth  in  front  of  the  small  tro- 
chanter :  it  gives  attachment  to  the  capsular  ligament,  the  united  crureus 
and  vastus  internus  muscles. 

The  shaft  is  arched  with  its  convexity  forward :  toward  the  middle  it 
is  partly  cylindrical,  and  expanded  below.  It  presents  anterior  and  lateral 
surfaces  without  definite  lines  of  demarcation.  All  these  surfaces  are 
covered  by  the  crureus  and  vasti  muscles.  Behind  the  lateral  surfaces 
are  separated  by  the  linea  aspera.  This  is  a  prominent  ridge  extending 
along  the  middle  third  of  the  shaft,  bifurcating  above  and  below.  The 
external  lip  is  prolonged  up  to  the  great  trochanter :  its  upper  end  is 
strongly  marked  for  the  gluteus  maximus,  constituting  the  gluteal  ridge. 
The  inner  lip  winds  round  below  the  small  trochanter,  merging  into  the 
anterior  intertrochanteric  line  and  forming  the  lower  part  of  the  spiral 
line :  rising  from  the  inner  lip,  a  third  fine  passes  up  to  the  small  tro- 
chanter and  gives  attachment  to  the  pectineus. 

Inferiorly  two  lips  are  prolonged  to  the  condyles  as  the  internal  and 
external  supracondylar  lines,  enclosing  the  flat  popliteal  surface  of  the 
6— A. 


82  BONES   OF   THE   LOWER   EXTREMITY. 

femur.  The  inner  line  is  interrupted  where  the  femoral  vessels  lie 
against  the  bone,  and  terminates  below  in  the  adductor  tubercle.  Above 
the  centre  of  the  linea  aspera  is  the  medullary  foramen,  directed  upward ; 
a  second  may  exist  near  the  lower  end  of  the  bone. 

To  the  inner  lip  of  the  linea  aspera  is  attached  the  vastus  internus,  to  the 
outer  lip  the  vastus  externus,  and  diagonally  between  the  two  the  adductor 
magnus.  Between  the  adductor  magnus  and  vastus  externus  are  the  gluteus 
maximus  and  short  head  of  the  biceps ;  between  the  adductor  magnus  and 
Vastus  internus  are  the  iliacus,  pectineus,  adductor  brevis,  and  adductor 
longus.  At  the  lower  part  of  the  popliteal  space  above  each  condyle  is  the 
origin  of  one  head  of  the  gastrocnemius,  and  externally  of  the  plantaris. 

The  inferior  extremity  presents  two  rounded  condyles^  united  in  front, 
but  separated  behind  by  the  intercondylar  notch :  the  external  is  broader 
and  more  prominent  in  front,  the  internal  longer  and  more  prominent 
internally.  The  inner  aspect  of  this  condyle  and  the  head  of  the  femur 
face  nearly  the  same  direction. 

The  inferior  surfaces  of  the  two  condyles  are  on  the  same  level  in  the 
natural  position  of  the  femur.  Opposite  the  front  of  the  intercondylar 
notch  the  whole  articular  surface  is  divided  by  a  faint  transverse  groove 
on  either  side  into  three  parts — a  convex  surface  on  either  condyle  for 
the  tibia  and  a  grooved  anterior  surface  for  the  patellar. 

The  patellar  surface  is  trochlear  in  form,  marked  by  a  vertical  hollow 
and  two  lips :  the  external  portion  is  wider,  more  prominent,  and  rises 
higher.  The  tibial  surfaces  are  nearly  parallel,  but  the  internal  one 
turns  outward  to  meet  the  patellar  surface.  The  exposed  lateral  surface 
of  each  condyle  presents  a  tuberosity  or  epicondyle  for  ligamentous  at- 
tachment. The  external  is  the  smaller :  above  it  is  the  impression  for 
the  outer  head  of  the  gastrocnemius ;  below  and  behind  it  is  an  oblique 
groove  ending  inferiorly  in  a  pit  from  which  rises  the  popliteus  muscle ; 
its  tendon  sinks  fully  into  the  groove  only  when  the  knee-joint  is  flexed. 
The  inner  head  of  the  gastrocnemius  rises  from  the  upper  part  of  the 
inner  condyle. 

The  intercondylar  fossa  Y)resents  two  impressions  for  crucial  ligaments: 
that  for  the  anterior  ligament  is  on  the  posterior  part  of  the  inner  sur- 
face of  the  external  condyle ;  that  for  the  posterior  ligament  is  on  the 
fore  part  of  the  external  surface  of  the  inner  condyle. 

The  cancellous  tissue  at  the  upper  end  of  the  femur  is  arranged  in  a  system 
of  "  pressure  lamellae  "  and  "  tension  lamellae  :  "  the  former  spring  from  the 
inner  side  of  the  neck  and  ascend  to  the  head  and  to  the  great  trochanter ; 
these  are  crossed  at  right  angles  by  the  tension  lamellai,  which  start  from  the 
outer  side  of  the  shaft  and  pass  upward  and  inward.  The  concave  side  of 
the  neck  is  further  strengthened  by  a  vertical  plate  of  compact  tissue,  the 
calcar  femorale,  just  in  front  of  the  small  trochanter. 

The  average  length  of  the  adult  European  femur  is  18  inches  for  the  male 
and  17  inches  for  the  female  ;  is  .275  of  the  stature,  and  its  proportion  to  the 
humerus  is  100  :  71.  The  inclination  of  the  femur  is  9°  with  the  sagittal  plane 
(the  two  bones  approach  each  other  below)  and  5°  with  the  frontal ;  it  is  also 
twisted  in  a  direction  opposite  to  that  of  the  humerus. 


THE   LEG.  83 

The  angle  of  the  neck  with  the  shaft  is  open  in  the  foetus  and  child,  then 
lessens  under  the  weight  of  the  body,  but  undergoes  no  change  after  growth 
is  completed.  The  upper  part  of  the  gluteal  ridge  may  form  a  third  trochanter, 
always  present  in  the  horse. 

In  place  of  or  in  addition  to  the  ridge  there  may  be  a,  fossa  hypotrochanterica. 
A  marked  development  of  the  linea  aspera  gives  a  pilastered  femur.  The  ad- 
ductor tubercle  may  be  of  large  size. 

The  femur  is  developed  from  one  primary  centre  and  four  epiphyses  ;  more 
of  growth  in  length  depends  upon  the  lower  epiphysis,  as  it  unites  last. 

Describe  the  patella. 

The  patella,  or  knee-pan,  is  a  sesamoid  bone  developed  in  the  tendon 
of  the  quadriceps  extensor  cruris.  It  is  somewhat  triangular,  with  its 
apex  below.  Its  anterior  surface  is  convex  and  striated  and  pierced  by 
vascular  foramina.  The  superior  border  is  broad  and  sloped  from  behind 
downward  and  forward,  and  gives  attachment  to  the  rectus  and  crureus 
portions  of  the  quadriceps  extensor. 

The  posterior  surface  of  the  bone  presents  two  vertical  and  two  trans- 
verse ridges :  one  vertical  ridge  is  close  to  the  inner  margin ;  the  other  is 
distinct  and  divides  the  surface  into  two  parts,  the  external  of  which  is 
the  larger  and  transversely  concave,  the  inner  smaller  portion  is  convex. 

The  faint  transverse  ridges  divide  the  articular  surface  into  an  upper 
two-sixths,  a  middle  three-sixths,  and  a  lower  one-sixth.  In  usual  ex- 
tension the  lower  one-sixth  is  in  contact  with  the  femur,  in  mid-flexion 
the  middle  three-sixths,  and  in  extreme  flexion  the  upper  two-sixths ;  also 
in  extreme  flexion  the  thin  marginal  facet  is  the  part  in  contact  with  the 
inner  condyle.  Below  the  articular  surface  is  a  rough  triangular  area  ; 
the  ligamentum  patellae  springs  from  the  apex. 

In  the  third  month  there  is  a  deposit  of  cartilage  in  the  quadriceps  tendon  ; 
ossification  begins  from  one  centre  in  the  third  year  and  is  completed  at 
puberty. 

THE  LEG. 
Describe  the  tibia. 

The  tibia  (flute),  or  shin-bone,  is  the  inner  and  anterior  of  the  two 
bones  of  the  leg,  and  transmits  the  weight  of  the  trunk  to  the  foot.  It 
articulates  with  the  femur,  fibula,  and  astragalus ;  has  a  shaft  and  two 
extremities. 

The  superior  extremity,  or  head,  is  thick  and  broad  transversely.  It 
forms  on  each  side  a  tuherosity,  on  the  upper  aspect  of  which  is  a  con- 
cave  articular  surface  for  the  condyles  of  the  femur.  The  internal  tuber- 
osity is  larger  than  the  external,  and  marked  posteriorly  by  a  horizontal 
groove  for  the  semimembranosus.  The  external  tuberosity  at  the  junc- 
tion of  the  anterior  and  outer  surfaces  forms  a  prominent  tubercle  for 
the  insertion  of  the  ilio-tibial  band ;  below  this  are  often  attached  a  few 
fibres  of  the  extensor  longus  digitorum  and  of  the  biceps.  At  the  pos- 
terior and  under  part  is  a  flat  articular  surface  for  the  fibula,  looking 
down,  out,  and  back.     The  internal  condylar  surface  is  oval,  more  hoi- 


84  BONES   OF   THE   LOWER   EXTREMITY. 

lowed  than  the  external,  and  longer  ;  the  external  is  nearly  circular,  con- 
cave from  side  to  side,  and  more  or  less  convex  from  before  backward  ; 
it  is  prolonged  a  little  posteriorly  where  the  popliteus  glides.  The 
periphery  of  each  articular  surface  is  flattened  for  the  semilunar  fibro- 
cartilage. 

Between  the  condylar  parts  is  an  interval  depressed  in  front  and  behind 
for  attachment  of  crucial  ligaments,  and  elevated  in  the  middle,  forming 
the  spine^  the  summit  of  which  presents  two  compressed  tubercles  with 
an  intervening  hollow.  The  depression  behind  the  spine  is  continued 
into  the  popliteal  notch,  which  separates  the  tuberosities  posteriorly. 
Anteriorly,  at  the  junction  of  the  head  and  shaft,  is  the  tubercle  or  ante- 
rior tuberosity  for  attachment  of  the  ligamentum  patellae. 

The  shaft  is  three-sided,  diminishing  in  size  as  it  descends  for  about 
two-thirds  of  its  length,  and  then  increasing  again.  The  internal  surf  ace 
is  convex  and  nearly  subcutaneous.  At  the  inner  side  of  the  tubercle 
are  the  insertions  of  the  gracilis,  semitendinosus,  and  double  insertion  of 
the  sartorius.  The  anterior  border  runs  sinuously  from  the  tubercle  to 
the  front  of  the  inner  malleolus :  its  upper  two-thirds  is  the  crest  of 
the  tibia,  its  lower  third  is  smooth.  The  external  surface  is  hollowed  in 
its  upper  two-thirds,  where  it  lodges  the  tibialis  anticus ;  below  this  the 
surface  turns  forward  and  is  covered  by  the  extensor  tendons.  The 
upper  third  of  the  posterior  surface  is  crossed  obliquely  J3y  the  popliteal 
or  oblique  line,  running  down  and  inward :  it  gives  origin  to  the  soleus. 
Above  it  is  a  triangular  area  occupied  by  the  popHteus;  below  it,  in 
the  middle  third  of  the  shaft,  is  a  longitudinal  ridge  marking  off  two 
portions,  an  inner  for  the  flexor  long,  dig.,  and  an  outer  for  the  tibialis 
posticus.  Below  the  oblique  line  a  large  medullary  canal  runs  down- 
ward. The  posterior  surface  is  separated  from  the  internal  by  the  inter- 
nal border,  which  is  most  distinct  in  the  middle  third,  from  the  external 
surface  by  the  external  border  or  interosseous  ridge. 

The  inferior  extremity  is  broad  from  side  to  side,  and  projects  down- 
ward internally  to  form  the  inner  malleolus.  This  malleolus  is  marked 
posteriorly  by  a  groove  for  the  tibialis  posticus  tendon,  and  more  exter- 
nally by  a  depression  for  the  flex.  long.  poll.  The  external  surface  of 
the  extremity  is  hollowed  for  the  fibula,  and  rough  for  ligaments  except 
along  the  lower  border.  Below  is  an  articular  surface,  quadrilateral, 
concave,  narrower  behind  than  in  front.  It  shows  a  slight  median  ele- 
vation separating  two  lateral  depressions.  Internally  the  cartilaginous 
surface  is  continued  upon  the  inner  malleolus. 

The  ratio  of  the  length  of  the  femur  to  that  of  the  tibia  is  100:  81  in  the 
European,  or  100  :  86  in  the  Bushman.  The  tibia  is  twisted  with  an  angle  of 
torsion  of  5°  to  20°.  The  shaft  may  be  much  compressed  laterally,  so  that 
the  skin  and  posterior  longitudinal  ridge  are  very  prominent ;  such  bone  is 
platycneniic. 

A  facet  at  the  anterior  margin  of  the  inferior  extremity  for  articulation 
with  the  neck  of  the  astragalus  is  rare  in  Europeans,  but  common  in  lower 
races  of  men. 


THE   LEG.  85 

The  tibia  is  developed  from  three  centres:  the  secoudary  one  for  the  upper 
extremity  usually  appears  before  birth.  The  tubercle  may  have  a  separate 
centre. 


Describe  the  fibula. 

The  fibula  (clasp),  or  peroneal  bone,  nearly  equals  the  tibia  in  length ; 
its  purpose  in  the  leg  is  mainly  for  elasticity.  Its  shaft  is  convex  back- 
ward, and  its  lower  extremity  is  placed  a  little  in  advance  of  the  upper. 

The  upper  extremity,  or  head,  is  prolonged  upward  at  its  back  part 
into  the  styloid  process ;  inside  this  is  a  facet  looking  upward,  inward, 
and  forward  for  articulation  with  the  tibia ;  more  externally  is  a  slight 
excavation  for  the  biceps ;  the  peroneus  longus  is  attached  in  front  and 
soleus  behind.     A  somewhat  constricted  part  below  the  head  is  the  neck. 

The  lower  extremity,  or  external  malleohis,  is  pyramidal  and  longer  than 
the  internal  malleolus ;  internally  it  shows  a  triangular,  smooth,  articular 
surface  for  the  astragalus,  and  behind  this  a  depression  for  the  posterior 
band  of  the  external  lateral  ligament. 

Posteriorly  is  a  shallow  groove  for  the  peroneus  longus  and  brevis 
tendons.     Externally  this  extremity  is  convex  and  subcutaneous. 

The  shaft  presents  four  surfaces — anterior,  posterior,  internal,  and 
external;  and  four  borders — antero-external,  antero-internal,  postero- 
external, and  postero- internal  (Gray). 

The  antero-external  harder  begins  in  front  of  the  head  and  bifurcates 
below  to  embrace  the  triangular  subcutaneous  surface  of  the  external 
malleolus:    this  border  is  between  the  peroneal  and  extensor  muscles. 

The  antero-internal  border,  or  interosseous  ridge,  is  close  to  the  pre- 
ceding and  parallel  with  it  in  the  upper  third.  It  terminates  below  at 
the  apex  of  a  rough  surface  just  above  the  articular  facet.  The  attached 
interosseous  membrane  separates  the  extensors  in  front  from  the  tibialis 
posticus  behind. 

The  postero-external  border  commences  at  the  base  of  the  styloid  pro- 
cess and  terminates  below  in  the  posterior  border  of  the  external  mal- 
leolus. It  is  directed  out  above,  then  back,  then  slightly  inward  below. 
It  separates  the  peronei  from  the  flexor  muscles.  The  poster o-internal 
border,  or  oblique  line,  commences  inside  the  head,  and  ends  by  joining 
the  interosseous  ridge  in  the  lower  fourth  of  the  bone. 

The  anterior  surface  is  very  narrow  above,  broader  and  grooved 
below;  to  it  is  attached  the  extensor  prop,  poll.,  the  extensor  long, 
dig.,  and  peroneus  tertius. 

The  external  surface  is  directed  outward  above  and  backward  below, 
and  is  occupied  by  the  peroneus  brevis  and  longus  muscles. 

The  internal  surface  between  the  antero-internal  and  postero-internal 
borders  is  grooved  for  the  tibialis  posticus. 

The  posterior  surface  looks  backward  above  and  directly  inward  be- 
low.^ Its  upper  third  attaches  the  soleu^  muscle ;  its  lower  part  is  rouffh 
for  interosseous  ligaments ;  to  the  rest  of  the  surface  is  attached  the 


86  BONES   OF   THE   LOWER   EXTREMITY. 

flexor  long.  poll.     The  medullary  canal  opens  on  this  surface  and  is 
directed  downward. 

The  fibula  is  developed  from  three  centres :  the  centre  for  the  lower  epiph- 
ysis appears  first  and  unites  first,  contrary  to  the  general  rule ;  sometimes 
the  medullary  canal  runs  toward  the  knee.  The  fibula  in  the  embryo  is  nearly 
as  large  as  the  tibia,  is  not  twisted,  and  articulates  with  the  femur.  The 
tibial  malleolus  at  first  is  larger  than  the  fibular ;  the  prominence  of  the  latter 
is  acquired  after  birth. 

THE  FOOT. 
Name  the  bones  constituting  the  tarsus. 

The  tarsus  is  composed  of  seven  bones — the  calcaneum  or  os  calcis,  and 
the  astragalus,  forming  the  hind-foot,  the  navicular  or  scaphoid,  three 
cuneiform,  and  cuboid,  forming  the  fore-foot. 

Describe  the  os  calcis. 

The  OS  calcis  (heel)  is  the  largest  bone  of  the  foot :  it  articulates  with 
the  astragalus  above  and  cuboid  in  front ;  its  principal  axis  runs  down- 
ward and  forward.  The  bone  presents  six  surfaces.  The  posterior  ex- 
tremity^ or  tuberosity^  presents  inferiorly  two  tubercles :  the  inner  is  the 
larger.  Its  posterior  surface  presents  three  districts — a  smooth  one  for 
a  bursa,  a  ligamentous  one  for  the  tendo  Achillis,  and  a  lower  convex 
part  for  the  pad  of  <the  heel.  The  part  in  front  of  the  tuberosity  forms 
a  slightly  constricted  neck. 

The  internal  surface  is  deeply  concave,  and  surmounted  above  by  the 
sustentaculum  tali  (support  of  the  astragalus) :  this  projects  inward  on  a 
level  with  the  upper  surface,  and  is  grooved  beneath  for  the  flexor  long, 
poll.  The  superior  surface  has  two  articular  facets,  separated  by  a  groove 
which  runs  forward  and  outward  for  the  interosseous  ligament.  The  an- 
terior facet,  often  subdivided  into  two,  is  on  the  sustentaculum,  and  is 
concave  longitudinally ;  the  other  one  is  convex.  At  the  fore  part  of 
the  groove  is  a  roughness  for  the  extensor  brevis  digit.  Behind  the 
articular  surfaces  is  a  region  convex  from  side  to  side  and  concave  from 
before  backward :  above  it  is  placed  adipose  tissue  in  front  of  the  tendo 
Achillis. 

The  anterior  surface  is  concavo-convex  for  articulation  with  the  cuboid. 
The  inferior  surface^  in  front  of  the  tuberosity,  projects  in  an  anterior 
tubercle  with  a  transverse  groove  in  front,  and  gives  attachment  to  an 
inferior  calcaneo-cuboid  ligament. 

The  external  surface  is  usually  flat,  and  presents  near  the  centre  a 
tubercle  for  the  middle  fasciculus  of  the  external  lateral  ligament,  and 
anteriorly  often  a  peroneal  spine^  separating  two  grooves — the  upper  for 
the  peroneus  brevis  tendon,  the  lower  for  that  of  the  peroneus  longus. 

Describe  the  astragalus. 

The  astragalus  (a  die),  or  talus,  receives  the  weight  of  the  body  from 
the  leg.     It  articulates  with  four  bones — the  tibia  above  and  internally, 


THE   FOOT.  87 

the  fibula  externally,  os  calcis  below,  and  scaphoid  in  front.  Its  long 
axis  is  forward  and  inward.  The  main  part  is  the  hody^  the  convex  an- 
terior portion  the  liead^  just  behind  which  is  the  neck.  The  superior 
articular  surface  occupies  the  whole  of  the  upper  surface  of  the  body 
and  sends  a  prolongation  down  on  either  side.  The  trochlear  part  is 
convex  and  slightly  concave  from  side  to  side,  wider  in  front  than 
behind ;  its  outer  margin  is  longer  than  the  inner,  and  curved,  while 
the  inner  is  straight.  The  inner  lateral  part  is  sickle-shaped  for  the 
internal  malleolus ;  the  outer  lateral  part  is  concave  and  triangular  and 
articulates  with  the  external  malleolus.  In feriorly  there  are  two  articular 
surfaces  for  the  calcaneum :  the  posterior  one  is  concave,  separated  by 
the  interosseous  groove  from  the  anterior  one,  which  is  convex.  The 
head  articulates  amteriorly  with  the  scaphoid :  at  the  lower  and  inner 
part,  between  this  and  the  anterior  articulation  for  the  os  calcis,  is  a 
facet  resting  upon  the  inferior  calcaneo-scaphoid  ligament,  the  three 
forming  one  continuous  surface.  The  posterior  surface  is  small  and  nar- 
row, and  marked  by  a  groove  for  the  flexor  long.  poll.  Bounding  the 
groove  are  two  tubercles,  the  external  more  prominent  and  giving  attach- 
ment to  the  posterior  band  of  the  ext.  lat.  ligament. 

Describe  the  scaphoid  bone. 

The  scaphoid,  or  navicular  bone,  is  placed  between  the  astragalus  and 
cuneiform  bones.  It  is  long  transversely,  and  presents  posteriorly  an 
articular  cavity  for  the  head  of  the  astragalus,  and  anteriorly  a  convex 
surface  divided  into  three  facets.  The  superior  surface  is  convex  and 
rough  for  ligaments ;  the  lower  is  narrower  and  irregular.  At  the  outer 
end  may  be  a  facet  for  articulation  with  the  cuboid.  The  inner  end 
forms  a  prominent  tuhei^osity,  directed  downward  for  insertion  of  the 
tibialis  posticus  tendon.  It  articidates  with  the  astragalus,  three  cunei- 
form, and  sometimes  the  cuboid. 

Describe  the  cuneiform  bones. 

The  cuneiform  (wedge-shaped)  bones  are  called  first,  second;  and  third 
from  within  out,  or  the  internal,  middle,  and  external :  they  are  placed 
between  the  scaphoid  and  inner  three  metatarsals ;  the  internal  is  the 
largest,  the  middle  the  smallest. 

The  internal  cuneiform  has  its  sharp  border  directed  up,  and  its  thick 
rounded  base  projects  downward.  The  anterior  articular  surface  for  the 
first  metatarsal  is  larger  than  the  posterior,  is  kidney-shaped,  and  is  con- 
vex. The  internal  surface  is  free  and  uneven,  and  marked  by  an  oblique 
groove  ending  in  an  oval  facet  for  the  tendon  of  the  tibiahs  anticus. 
On  the  outer  surface,  along  the  superior  and  posterior  borders,  is  an 
L-shaped  facet  for  the  middle  cuneiform,  and  anteriorly  a  facet  for  the 
second  metatarsal.  Articulates  with  four  bones — scaphoid,  middle  cunei- 
form, first  and  second  metatarsal. 

The  middle  cuneiform  has  its  base  directed  upward  and  sharp  edge 


88  BONES   OF   THE   LOWER   EXTREMITY. 

downward :  the  anterior  end  is  narrower  than  the  posterior,  and  articu- 
lates with  the  second  metatarsal.  On  the  inner  side  is  an  L-shaped  facet 
for  the  internal  cuneiform,  and  on  the  outer  side  posteriorly  a  facet  for 
the  external  cuneiform.  Articulates  with  four  bones — scaphoid,  internal 
and  external  cuneiform,  and  second  metatarsal. 

The  external  cuneiform  has  its  base  upward.  Its  anterior  end  is  trian- 
gular for  the  third  metatarsal,  and  continuous  with  it  are  small  lateral 
facets  for  the  second  and  fourth  metatarsal.  On  the  posterior  part  of 
the  inner  surface  is  a  facet  for  the  middle  cuneiform,  and  on  the  outer 
surface  a  larger  one  for  the  cuboid.  Articulates  with  six  bones — scaphoid, 
middle  cuneiform,  cuboid,  second,  third,  and  fourth  metatarsal. 

Describe  the  cuboid  bone. 

The  cuboid  is  on  the  outer  side  of  the  foot  between  the  calcaneum  and 
fourth  and  fifth  metatarsals.  It  is  pyramidal  rather  than  cuboid  by  the 
sloping  of  four  surfaces  to  the  short  external  border.  If  the  base  of  the 
bone  were  external,  the  lateral  thrust  of  the  cuneiforms  would  throw  it 
out  of  the  arch. 

Posteriorly  it  articulates  with  the  os  calcis  by  a  concavo-convex  sur- 
face, and  its  lower  internal  corner  projects  back  beneath  that  bone. 

The  anterior  surface,  smaller  than  the  posterior,  shows  an  internal 
quadrilateral  and  an  external  triangular  facet  for  the  fourth  and  fifth 
metatarsals.  In  the  middle  of  its  internal  surface  is  a  facet  for  the  ex- 
ternal cuneiform,  and  behind  this  often  a  smaller  one  for  the  scaphoid. 
The  superior  surface  is  rough  for  ligaments.  On  the  inferior  surface  is 
a  thick  ridge  or  tuberosity^  at  the  outer  end  of*  which  is  a  smooth  facet 
where  the  peroneus  longus  tendon  turns  into  the  sole :  in  front  of  the 
tuberosity  is  a  groove  for  the  tendon,  and  behind  it  a  depression  for  the 
calcaneo-cuboid  ligament.  Articulates  with  four  bones — os  calcis,  exter- 
nal cuneiform,  fourth  and  fifth  metatarsal,  and  sometimes  with  the 
scaphoid. 

A  reduction  in  the  number  of  tarsal  bones  may  occur  from  a  congenital 
synostosis  of  the  os  calcis  and  scaphoid,  os  calcis  and  astragalus,  or  astragalus 
and  scaphoid.  An  increase  may  arise  from  the  separation  of  the  external 
tubercle  at  the  back  of  the  astragalus  (os  trigonum),  a  separation  of  the  tuber- 
osity of  the  scaphoid,  or  a  division  of  the  internal  cuneiform  into  two  pieces : 
a  supernumerary  ossicle  may  occur  at  the  front  of  the  os  calcis  or  at  the  front 
of  the  internal  cuneiform. 

Describe  the  metatarsus. 

The  five  metatarsals  resemble  the  metacarpals ;  are  slightly  convex  on 
the  dorsum,  are  three-sided,  and  have  rounded  heads.  The  first  is 
short,  thick,  and  massive  :  on  the  base  is  a  large  kidney-shaped  facet  for 
the  internal  cuneiform,  sometimes  a  lateral  facet  on  the  outer  side  for 
the  second  metatarsal.  The  lower  part  of  the  base  forms  the  tuberosity, 
projecting  down  and  out  and  presenting  an  impression  for  the  peroneus 
longus.     On  the  inner  side  is  a  small  mark  for  the  tibialis  anticus.     The 


THE   FOOT.  89 

superior  surface  of  the  shaft  looks  inward  :  the  inferior  is  concave,  the 
external  triangular  and  flat.  The  head  is  large,  and  shows  inferiorly  a 
median  ridge  separating  two  grooves  in  which  the  sesamoid  bones  glide. 
The  remaining  four  bones  are  distinguished  from  the  metacarpals  by 
being  more  slender  and  compressed,  corresponding  to  a  form  of  foot 
narrower  than  that  of  the  hand.  Their  heads  are  elongated  from  above 
down,  and  end  below  in  two  small  projections.  On  each  side  are  a  tubercle 
and  depression  for  the  lateral  ligament.  Their  bases  furnish  distinctions. 
The  second  has  a  triangular  base  articulating  with  the  middle  cuneiform  : 
on  its  inner  side  is  a  small  facet  for  the  internal  cuneiform,  and  some- 
times a  small  one  for  the  first  metatarsal.  On  the  outer  side  is  an  upper 
and  lower  facet,  each  subdivided  into  two,  making  four :  the  two  poste- 
rior articulate  with  the  external  cuneiform;  the  two  anterior  with  the 
third  metatarsal.  The  third  has  a  triangular  base  for  the  external  cunei- 
form :  on  the  inner  side  are  two  facets  for  the  second,  and  on  the  outer 
side  a  single  one  for  the  fourth.  The  fourth  has  an  oval  or  quadrangular 
base  for  the  cuboid :  on  the  inner  side  is  usually  a  double  facet  for  the 
third  metatarsal  and  external  cuneiform,  and  on  the  outer  side  a  single 
one  for  the  fifth.  The  fifth  articulates  internally  with  the  fourth,  and 
behind  by  an  obliquely  cut  surface  with  the  cuboid :  it  projects  exter- 
nally into  a  large  tuberosity  into  which  the  peroneus  brevis  is  inserted. 
An  independent  ossicle  may  take  the  place  of  this  tuberosity. 

Two  sesamoid  bones  lie  side  by  side  in  the  plantar  wall  of  the  first 
metatarso-phalangeal  joint.    There  may  be  small  ones  for  the  other  toes. 

Describe  the  phalanges. 

The  phalanges  of  the  toes  correspond  closely  to  those  of  the  fingers. 
Those  of  the  four  outer  toes  are  smaller  than  those  of  the  hand,  but 
those  of  the  great  toe  are  larger  than  those  of  the  thumb.  The  shafts 
of  the  first  row  are  compressed  laterally ;  those  of  the  second  row,  espe- 
cially in  the  fourth  and  fifth  toes,  are  hardly  longer  than  their  breadth. 
The  last  two  phalanges  of  the  little  toe  may  be  ankylosed  (36  per  cent.) 
as  frequently  in  the  infant  as  in  the  adult. 

Ancient  art  represents  the  second  toe  as  longer  than  the  great  toe.  This 
may  have  been  copied  from  some  lower  race,  but  in  the  present  white  races 
the  great  toe  is  longer  in  nearly  all  cases. 

Describe  the  bones  of  the  foot  as  a  whole. 

The  foot  is  narrowest  at  the  heel,  and  broadens  as  far  as  the  meta- 
tarsal bones.  The  astragalus  overhanging  the  sustentaculum  tali  inclines 
inward  so  much  that  its  external  border  is  over  the  middle  line  of  the  os 
calcis.  The  foot  is  arched  longitudinally  from  the  heel  to  the  heads  of 
the  metatarsals-^a  double  arch  in  front  and  a  common  support  behind. 
The  internal  division  of  the  arch  is  most  raised,  and  consists  of  the  pos- 
terior two-thirds  of  the  calcaneum,  the  scaphoid,  cuneiform,  and  three 


90  BONES   OF   THE   LOWER   EXTREMITY. 

inner  metatarsals ;  the  outer  arch  consists  of  the  whole  length  of  the  cal- 
caneum,  the  cuboid,  the  fourth  and  fifth  metatarsals.  There  is  also  a 
transverse  arch  formed  by  the  cuboid  and  three  cuneiform,  and  in  front 
by  the  metatarsals. 

In  the  infant  the  head  of  the  astragalus  is  directed  more  inward  than  in 
the  adult,  and  the  foot  is  inverted.  The  first  metacarpal  is  also  short  and 
inclined  inward,  the  young  foot  resembling  that  of  an  ape. 

The  tarsal  bones  are  all  ossified  in  cartilage  froln  a  single  nucleus,  except- 
ing the  OS  calcis,  which  has  an  epiphysis  on  the  posterior  extremity.  The 
metatarsals  and  phalanges  agree  with  the  corresponding  bones  of  the  hand, 
each  from  a  principal  centre,  and  one  secondary  one :  the  four  outer  meta- 
tarsals have  the  epiphysis  at  the  distal  extremity ;  in  the  metatarsal  of  the 
great  toe  and  in  the  phalanges  the  epiphyses  are  at  the  proximal  ends. 

What  are  some  of  the  homological  comparisons  of  the  upper  and 
lower  limbs  ? 

The  peripheral  parts  of  both  limbs  in  man  and  animals  show  a  quinquefid 
division,  but  certain  vestiges  of  suppressed  digits  give  reasons  for  believing 
that  this  division  was  preceded  by  one  of  seven  (heptadactyle).  The  nerves 
entering  into  the  limb  plexuses  are  in  each  case  seven  (crural  plexus  being 
composed  of  the  lumbar  and  sacral). 

The  thoracic  and  pelvic  limbs  are  constructed  on  the  same  general  type, 
modified  according  to  use — e.  g.  in  the  upper  limb  of  man  the  free  motion  of 
the  shoulder-joint,  the  eversion  of  the  humerus,  the  forward  flexion  of  the 
elbow,  the  pronation  and  supination  of  the  hand,  the  opposability  of  the 
thumb,  all  show  this  to  be  an  organ  of  prehension  and  touch  and  subservient 
to  the  head ;  in  the  lower  limb  the  fixed  condition  of  the  pelvic  girdle,  the 
greater  strength  of  bones,  the  close-fitting  hip-joint,  the  backward  flexion  of 
the  knee,  and  non-opposability  of  the  great  toe,  all  have  relation  to  stability, 
locomotion,  and  support  of  weight. 

Figs.  4  and  5  show  the  junctions  of  the  limb-stalks  to  the  trunk :  the  bones 
of  the  trunk  are  black,  those  of  the  girdles  shaded.  The  shoulder  girdle  is 
imperfect  in  front,  and  completed  by  the  sternum ;  it  is  wholly  incomplete 
behind.     The  pelvic  girdle  is  perfect  in  front,  and  is  completed  behind  by  the 


,ni!||ll 


Fig.  4. 


Shoulder  Girdle  (Henle). 

sacrum,  giving  solidity  in  marked  contrast  to  the  mobility  of  the  upper  girdle. 
The  dorsal  portions  of  the  girdles  are  the  scapula  and  ilium :  the  ventral  por- 
tion is  in  each  case  double,  including  the  clavicle  and  coracoid  above,  the 


THE   FOOT.  91 

pubis  and  ischium  below.  The  coracoid  and  ischium  correspond  :  the  clavicle 
may  correspond  to  the  reptilian  precoracoid,  which  represents  the  pubis.  The 
subscapular  fossa  represents  the  gluteal  surface  of  the  ilium,  as  the  scapula 
has  been  rotated  out  and  the  ilium  inward,  in  accordance  with  the  rotation 
of  the  free  parts  of  the  limbs. 

In  the  earliest  stage  the  limbs  bud  out  and  have  a  dorsal  and  ventral  aspect : 
in  the  next  stage,  when  they  come  to  be  folded  against  the  body,  one  border 
will  look  toward  the  head  (preaxial)  and  one  toward  the  tail  (postaxial).  Thus 

Fig.  5. 

.Jill  _  p^ 


Pelvic  Girdle  (Henle). 

the  great  tuberosity  of  the  humerus,  its  radial  condyle,  the  radius,  and  thumb, 
the  small  trochanter  of  the  femur,  its  internal  condyle,  the  tibia,  and  great 
toe,  are  preaxial.  In  higher  animals  and  man  further  changes  occur  accord- 
ing to  function.  The  humerus  in  man  is  rotated  out  about  45°,  so  that  its 
radial  condyle  becomes  external ;  the  femur  is  rotated  in  about  90°,  bringing 
the  tibial  condyle  to  the  inner  side. 

The  pisiform  of  the  carpus  has  been  considered  a  sesamoid  bone  in  the  ten- 
don of  the  flexor  carp.  uln. :  it  may  be  the  representative  of  a  suppressed 
digit.  The  tuberosity  of  the  scaphoid  of  the  carpus  and  of  the  navicular  of 
the  tarsus  correspond,  and  may  each  represent  a  suppressed  digit. 

Table  of  Homologous  Bones  in  Thoracic  and  Pelvic  Limbs. 
Thoracic  Limb.                                               Pelvic  Limb. 
Scapula Ilium. 

Precoracoid Pubis. 

Coracoid Ischium. 

Glenoid  cavity  ^ • Cotyloid  cavity. 

Clavicle    ....'. Absent. 

Humerus        Femur. 

Great  tuberosity Small  trochanter. 

Small  tuberosity Great  trochanter. 

External  condyle  and  capitellum    .    .    .      Internal  condyle. 

Internal  condyle  and  trochlea External  condyle. 

Absent Patella. 

Eadius Tibia. 

Ulna Fibula. 

Carpus      Tarsus. 

Metacarpus Metatarsus. 

Pollex Hallex. 

Digital  phalanges Digital  phalanges. 


92  BONES   OF   THE   LOWER   EXTREMITY. 

Homologues  of  Carpus  and  Tarsus. 
Carpus.  Tarsus. 

irXm'''} 0--1-- 

Soid}  A^*-^»i»«- 

Tuberosity  of  scaphoid  j Navicular. 

US  centrale  j 

Trapezium Internal  cuneiform. 

Trapezoid Middle  cuneiform. 

Os  magnum External  cuneiform. 

Unciform Cuboid. 

Comparisons  of  Stability  in  Hayid  and  Foot. 

Stability.  Intermediate       Mobility. 

{carpus 2 
metacarpus 3 
phalanges 5 

{tarsus 5 
metatarsus 3 
phalanges 2 

Homologous  Parts  of  Scapula  and  Ilium. 
Scapula.  Ilium. 

Supraspinous  fossa Sacral  surface. 

Infraspinous  fossa Iliac  fossa. 

Subscapular  fossa    ......  Gluteal  surface. 

Spine  and  acromion Ilio-pectineal  line. 

Superior  border Posterior  border. 

Axillary  or  glenoid  border  .    .    .  Anterior  or  cotyloid  border. 
Base  (vertebral  border)    ....  Iliac  crest. 

Superior  angle Posterior  superior  spine. 

Inferior  angle Anterior  superior  spine. 

What  facts  show  the  adaptation  of  the  skeleton  to  the  erect 
attitude  ? 

For  maintaining  this  position  the  muscles  passing  over  the  ankle-joint 
must  constantly  act:  at  the  knee-  and  hip-joints  the  ligaments  are  more  con- 
cerned. A  vertical  plane  through  the  vertex  of  the  skull  passes  through  the 
occipito-atlantoid,  lumbo-sacral,  sacro-iliac,  hip-,  knee-,  and  ankle-joints.  In 
the  infant  the  size  of  the  head  amounts  to  nearly  one-fifth  of  the  body,  and 
the  middle  distance  between  the  vertex  and  sole  of  the  foot  is  above  the  um- 
bilicus ;  in  the  adult  a  similar  point  is  near  the  symphysis  pubis.  The  skull 
is  nearly  balanced,  and  the  plane  of  the  foramen  magnum  is  nearly  horizon- 
tal. The  face  and  orbits  look  forward,  the  nostrils  down.  The  spinal  column 
is  pyramidal  and  fitted  to  sustain  weight.  The  thorax  is  compressed  antero- 
posteriorlj^,  carrying  the  centre  of  gravity  backward  near  the  spine.  The 
iliac  portion  of  the  pelvis  supports  the  abdominal  viscera.  The  femur  is 
longer  than  the  tibia,  to  give  sufficient  extent  of  stride  and  powers  of  bal- 
ancing.   The  upper  limb  is  adjusted  for  mobility,  and  not  for  support.     The 


ARTHBOLOGY. 


93 


foot  of  man  alone  among  animals  has  an  arched  instep.    The  great  toe  is  con- 
stituted not  for  grasping,  but  for  support. 


ARTHROLOGY. 
What  are  the  structures  forming  joints  ? 

Bones,  cartilage,  ligaments,  and  synovial  membrane  enter  into  the 
formation  of  joints. 

The  articular  portions  of  bones  are  enlarged  to  form  a  joint  of  suitable 
•size,  and  so  that  muscles  passing  over  the  joint  can  act  at  a  greater  angle. 
The  layer  of  bone  beneath  the  cartilage  is  a  compact  articular  lamella. 
The  cartilage  is  usually  hyaline,  may  be  fibro-cartilage  or  yellow  elastic. 

The  ligaments  are  mainly  white  fibrous  tissue  ;  some  are  yellow  elastic. 

The  synovial  membrane  is  like  a  short  wide  tube  covenng  the  inner 
surface  of  the  ligaments ;  its  secretion  is  synovia,  95  per  cent,  water,  3.51 
per  cent,  albumin  and  salts.  There  are  three  kinds  of  synovial  mem- 
brane— articular,  bursal,  and  vaginal.  The  former  in  the  foetus  is  said 
to  cover  the  articular  cartilages  as  well  as  ligaments. 

The  hursce  are  mucous  as  between  integument  and  bone,  and  synovial 
between  muscles  or  tendons  and  bone. 

Vaginal  synovial  membranes  are  sheaths  for  tendons. 

What  is  the  classification  of  joints  ? 

Gray  classifies  them  as  synarthrodial,  immovable ;  amphiarthrodial, 
.  mixed ;  and  diarthrodial^  or  movable. 

vera       f  dentata — e.  g.  interparietal, 
f  (fpvig^  {  serrata — e.  g.  interfrontal. 

Sutura 


Synarthrodial, 
immovable 


Amphiarthro- 
dial,  mixed 


Diarthrodial, 
movable 


[limbosa — e.  g.  fronto-parietal. 
j  notha    f  squamosa — e.  g.  squamo-parietal. 
[  (false)  jharmonia — e.  g.  intermaxillary. 
Schindylesis — e.  g.  rostrum  of  sphenoid  and  vomer. 
^  Gom pilosis — e.  g.  tooth  in  alveolus. 

(1 )  Surfaces  connected  by  fibro-cartilage,  not  separated  by 

synovial  membrane — e.  g.  bodies  of  vertebrae. 

(2)  Surfaces  covered  by  fibro-cartilage  and  partially  lined 

by  synovial  membrane — e.  g.  pubic  symphysis. 
'  Arthrodia  gliding  (not  referable  to  any  axis) — e.  g.  some 

movements  in  temporo-maxillary  articulation. 
Enarthrosis,  ball-and-socket — e.  g.  shoulder  and  hip. 
Ginglymus^  hinge— 6.  g.  elbow,  knee  ;  no  lateral  motion. 
■{  Diarthrosis  rotatoria^  or  lateral  ginglymus,  a  pivot  within 
a  ring — e.  g.  atlo-axoid. 
Condyloid^  ovoid  head  in  elliptical  cavity — e.  g.  wrist. 
Reciprocal  reception^  saddle-shaped — e.  g.  carpo-meta- 
t         carpal  joint  of  thumb. 


94  henle's  classification  of  joints. 

What  agents  keep  joint  surfaces  together  ? 

1.  Atmospheric  pressure — e.  g.  hip-joint ;  2.  synovial  fluid  ;  3.  liga- 
ments to  a  small  extent ;  4.  muscles,  important.  A  short  muscle  may 
act  on  more  than  one  joint ;  gluteus  maximus  extends  the  hip  and  also 
the  knee  through  the  rectus  f'emoris. 

What  limits  motion  in  joints  ? 

1.  Extent  of  articular  surfaces;  2.  bony  contact;  3.  approximation  of 
soft  parts  ;  4.  manner  of  articulation  ;  5.  anatomical  separation  of  joint 
into  two,  as  the  joints  of  a  vertebra. 

HENLE'S   classification   OF   JOINTS. 

I.  Synarthrodia ;  II.  Diarthrodia. 

I.  Synarthrodia — a  firm  joint;  characteristics  are  (1)  junction  along  entire 
extent  of  adjacent  surfaces  by  a  third  tissue;  (2)  motion  is  due  to  the  gliding 
of  this  tissue;  (3)  bones  do  not  touch. 

{a)  Synchondrosis,  where  intervening  tissue  is  remains  of  embryonal  tissue, 
not  hyaline,  but  fibrous  or  elastic — e.  g.  (1)  petrous  bone  and  jugular  process  ; 

(2)  sacro-iliac  and  intervertebral  articulations :  (3)  the  band  may  ossify,  synos- 
tosis— e.  g.  sphenoid  and  occipital  or  interfrontal  suture ;  (4)  small  space  hol- 
lowed out,  so  intervening  cartilage  is  incomplete  ;  hemiarthrosis,  or  false  syn- 
chondrosis. 

(6)  Syndesmosis,  a  suture.  Fibrous  or  membranous  tissue  intervenes  and 
motion  is  practically  nil ;  not  an  interlocking,  as  connective  tissue  is  inter- 
posed, but  the  union  is  strengthened  by  serrations. 

II.  Diarthrodia,  movable.  In  development  two  segments  of  bone  will  en- 
croach upon  a  middle  portion,  so  that  the  opposite  articular  surfaces  come  in 
contact.  The  enveloping  perichondrium  becomes  periosteum,  and  ultimately 
capsular  ligament.  At  the  periphery  of  a  concave  surface  may  be  developed 
a  fibro-cartilaginous  ring  or  glenoid  ligament. 

The  capsule  extends  only  to  the  hyaline  cartilage,  tough  externally  and 
difierentiated  internally  into  synovial  membrane. 

There  may  be  only  a  partial  deliquescence  of  blastema,  and  two  articular 
cavities  are  formed  with  interarticular  fibro-cartilage.  Next  the  bones  may 
be  in  actual  contact  by  a  liquefaction  in  part  of  the  intervening  substance, 
forming  hemiarthrodia :  the  pubic  symphysis  is  usually  synarthrodial,  but  in 
pregnancy  there  may  be  a  slight  liquefaction,  forming  an  hemiarthrodial 
joint.  A  continued  liquefaction  produces  a  diarthrodial  joint,  characterized 
by  (1)  direct  touch  of  opposed  surfaces;  (2)  bones  covered  by  articular  carti- 
lage; (3)  joint  enclosed  in  a  capsule.  There  is  no  proper  synovial  sac:  a 
change  occurs  on  the  inner  surface  of  the  cartilage  and  capsule  to  small  flat 
cells ;  the  synovial  fluid  fills  up  irregularities  and  makes  better  coaptation. 
Liquefaction  may  occur  in  such  a  way  as  to  produce  a  vertical  layer,  as  the 
crucial  ligaments. 

To  classify  special  joints  various  principles  of  subdivision  may  be  em- 
ployed:   (1)  coaptation  of  the  bones  forming  joints;  (2)  extent  of  surfaces; 

(3)  shape  of  surfaces.  There  are  no  special  names  given  to  the  first  variety : 
joints  with  non-coaptated  surfaces  are  very  numerous;  the  spaces  are  filled 
with  interarticular  cartilages  or  synovial  folds.  The  cartilage  may  remain 
fixed  or  it  may  move  on  the  joint-socket,  and  the  head  of  a  bone  move  on 
the  cartilage — a  sort  of  double  joint,  as  at  the  temporo-maxillary  and  knee- 


ARTICULATIONS   OF   THE   TRUNK    AND   HEAD.  95 

joints.  Almost  always  the  curve  of  the  joint-head  is  of  smaller  radius  than 
that  of  the  joint-socket. 

Joints  named  from  the  extent  of  articular  surfaces  are  amphiarthrodial 
(arthrodia  or  gliding  of  Gray) ;  characteristics  are  (1)  surfaces  plane  or 
nearly  so ;  (2)  extent  of  surface  the  same ;  (3)  firm,  dense  capsule ;  (4)  motion 
slight :  typical  examples  are  petro-occipital  and  ilio-sacral.  Joints  may  some- 
times change  from  one  variety  to  another  by  absorption  or  change  in  the  in- 
terarticular  tissue. 

Joints  named  according  to  shape  of  articular  surfaces  are — (1)  with  spherical 
surfaces,  ball-and-socket,  arthrodia!  (enarthrosis,  Gray) ;  (2)  with  elliptical  sur- 
faces, condylarthrosis,  as  radio-carpal ;  (3)  with  saddle-shaped  surfaces,  carpal 
joint  of  thumb;  (4)  with  cylindrical  surfaces:  {a)  hinge-joint,  ginglymus,  pro- 
duced by  a  cylindrical  surface  at  right  angles  to  the  shaft ;  the  cylinder  may 
hh  grooved  or  ridged  antero-posteriorly ;  (6)  screw-like  joint,  as  at  elbow,  where 
central  ridge  is  not  antero-posterior,  but  if  continued  would  form  the  thread 
of  a  screw;  (c)  rotation- joint,  trochoides  (lateral  ginglymus  of  Gray),  cylinder 
parallel  to  shaft.  (5)  Mixed  or  ginglymo-arthrodial,  metacarpo-phalangeal :  lat- 
eral ligaments  control  movement  in  certain  directions. 

The  motions  possible  in  joints  are  (1)  radial,  as  flexion  and  extension;  (2) 
rotatory ;  (3)  circumduction  ;  (4)  gliding. 

Flexion  lessens  the  angles  of  bones,  extension  increases  that  angle.  All  liga- 
ments besides  the  capsular  and  those  within  the  capsule  are  called  accessory : 
strengthening  bands  of  the  caf^sule,  and  separated  from  it  by  a  layer  of  con- 
nective tissue,  are  regarded  as  accessory  ligaments. 

ARTICULATIONS  OF  THE  TRUNK  AND  HEAD. 
What  are  the  articulations  of  the  trunk  and  head  ? 


1.  Of  the  vertebral  column. 

2.  Of  the  false  vertebrae. 

3.  Of   rotation    vertebrae    with 
each  other  and  with  occiput : 

(a)  atlas  with  axis; 
Q))  occiput  with  atlas ; 
(c)  occiput  with  axis. 


4.  Of  ribs  with  vertebrae. 

5.  Of  costal  cartilages  with  ster- 
num and  with  each  other. 

6.  Of  sternum. 

7.  Of  hyoid  bone. 
8. -Of  skull. 

9.  Of  lower  jaw. 


Articulations  of  the  vertebral  column  comprise  five  sets:  (1)  those 
between  the  bodies  of  the  vertebrae;  (2)  between  the  lamince;  (3)  be- 
tween the  articular;  (4)  ih^  spinous ;  (5)  and  the  transverse  processes. 

Describe  the  ligaments  of  the  bodies. 

Anterior  common,  posterior  common,  and  intervertebral  substance. 
The  anterior  common  extends  along  the  front  of  the  bodies,  filling  up 
the  concavities  of  the  vertebrae  from  the  axis  to  the  sacrum :  it  is 
broader  below  than  above,  and  thicker  opposite  the  front  of  the  body, 
where  it  is  loosely  connected,  than  opposite  the  intervertebral  disk, 
where  it  is  closely  connected.  It  consists  of  several  layers  of  fibres, 
the  superficial  set  extending  from  a  given  vertebra  to  the  fourth  or  fifth 
below  it,  and  a  third  deep  set  from  one  to  another.  The  ligament  splits 
for  the  passage  of  vessels  to  the  vertebral  body. 


96  ARTICULATIONS   OF   THE   TRUNK   AND   HEAD. 

The  2)osterior  common  Ugam^ent  is  inside  the  spinal  canal,  along  the 
posterior  surface  of  the  bodies,  and  extends  from  the  axis  to  the  sacrum, 
it  is  broader  above  than  below,  and  laterally  presents  a  series  of  denta- 
tions over  the  intervertebral  disks,  and  concavities  over  the  centres  of 
the  bodies,  from  which  it  is  sei)arated  by  the  venae  basis  vertebrae.  It 
has  denser  fibres  than  the  anterior  ligament,  and  is  similarly  divided  into 
sets. 

The  intervertebral  substances  are  disks  of  fibro-cartilage  placed  be- 
tween the  bodies  of  the  vertebrae  from  the  axis  to  the  sacrum.  They 
vary  in  size  and  thickness  in  the  diflPerent  regions,  being  thicker  behind 
than  in  front  in  the  lumbar  and  cervical  regions,  and  uniformly  thick  in 
the  dorsal  region.  They  form  about  one-fourth  of  the  spinal  column  or 
one-third  of  the  lumbar  region,  one-fourth  of  the  cervical,  and  one-fifth 
of  the  dorsal.  They  are  connected  with  the  anterior  and  posterior  com- 
mon ligaments,  and  in  the  dorsal  region  with  the  heads  of  ribs.  They 
are  composed  at  the  circumference  of  laminae  yJo  to  -^^  inch  (}  to  J  mm.) 
broad,  of  fibrous  and  fibro-elastic  tissue  and  fibro-cartilage  arranged  con- 
centrically one  within  the  other,  and  surrounding  in  the  centre  a  soft,  pulpy 
mass.  The  laminae  are  not  composed  of  difierent  materials,  but  owe  their 
difference  in  appearance  to  the  fact  that  they  are  obliquely  placed,  cross- 
ing each  other  like  an  X,  and  the  light  strikes  them  differently :  some  fibres 
run  horizontally.     The  most  external  fibres  resemble  those  of  a  tendon. 

The  central  part  is  pulpy,  soft,  and  yellow,  containing  cells  in  a  fibrous 
matrix :  it  rises  up  conically  when  pressure  is  removed.  The  interver- 
tebral disks  are  compressible,  and,  according  to  one  set  of  measurements, 
a  man  is  J  inch  taller  in  the  morning  than  at  night. 

Describe  the  ligaments  of  the  laminse  and  processes. 

Those  connecting  the  laminae  are  the  Ugamenta  subjlava,  of  yellow  elastic 
tissue  attached  to  the  anterior  surface  of  the  lamina  above  and  posterior 
surface  and  upper  margin  of  the  lamina  below.  They  are  analogous  to 
the  intervertebral  substances  in  front.  Each  ligament  consists  of  two 
lateral  portions,  which  commence  on  each  side  of  the  root  of  either  artic- 
ular process  and  pass  to  the  convergence  of  the  laminae.  They  do  not 
exist  between  the  occiput  and  atlas,  atlas  and  axis :  they  take  the  place 
of  active  material  and  help  muscles  pull  back  the  flexed  column. 

The  ligaments  of  the  articular  proce^sses  are  capsular^  thin,  loose  sacs 
attached  to  their  margins  and  completed  internally  by  the  ligamenta  sub- 
flava.     They  are  lined  by  synovial  membrane. 

The  mterspiiLOus  ligaments  are  thin  and  membranous,  extending  from 
near  the  root  to  the  summit  of  the  spinous  process.  They  are  slightly 
developed  in  the  neck,  narrow  in  the  dorsal  region,  and  thicker  in  the 
lumbar. 

The  supraspinouH  ligament  is  a  strong  cord  connecting  the  apices  of 
the  processes  down  from  the  seventh  cervical.  Its  most  superficial  fibres 
connect  three  or  four  vertebrae  and  its  deepest  neighboring  vertebrae. 

The  ligamentum  nuchce  continues  the  supraspinous  ligament  upward 


SPINAL  COLUMN,   ROTATION   VERTEBRJE.  97 

in  the  neck,  and  is  attached  to  the  external  occipital  protuberance.  In 
the  human  subject  it  is  only  an  intermuscular  septum  between  the  two 
trapezii.  A  fibrous  slip  is  given  oiF  from  its  anterior  surface  to  each  cer- 
vical spinous  process. 

The  intertransve)^se  ligaments  are  scattered  fibres  in  the  cervical  region, 
rounded  cords  in  the  dorsal,  and  membranous  in  the  lumbar. 

What  are  the  movements  of  the  spinal  column  ? 

Flexion,  extension,  lateral  movement,  circumduction,  and  rotation — 
all  on  three  axes,  one  transverse,  one  antero-posterior,  and  one  vertical. 
Flexion  is  the  freest  of  all  movements :  it  compresses  the  disks  in  front 
and  stretches  the  posterior  common  ligament  and  ligamenta  subflava. 
Extension  is  not  marked,  and  is  limited  by  the  anterior  common  liga- 
ment and  spinous  processes. 

Flexion  and  extension  are  most  free  in  the  lower  lumbar  region  and 
least  in  the  upper  dorsal :  extension  is  greater  in  the  neck  than  flexion. 
Lateral  movement  is  most  free  in  the  cervical  and  lumbar  regions,  hm- 
ited  by  the  approximation  of  transverse  processes.  Circumduction  is 
limited.  Rotation  is  free  in  the  upper  dorsal  and  absent  in  the  lumbar 
region.  So  the  cervical  region  enjoys  the  greatest  extent  of  each  variety : 
the  dorsal  has  greatest  rotation,  while  the  lumbar  has  none.  We  can  turn 
the  head  and  trunk  through  180°  on  either  side,  head  and  neck  through 
79° — three-fifths  of  it  is  between  atlas  and  axis ;  back  and  loins  through 
28°  ;  and  in  joints  below  this  through  73°. 

The  movements  are  due  largely  to  the  shape  of  the  disks,  which  limit 
the  extent  of  motion,  but  not  the  direction ;  it  is  proportional  to  their 
height  and  inversely  as  their  area. 

The  vertebral  articulations  are  supplied  by  the  spinal  nerves  in  each 
region :  by  the  vertebral  and  ascending  cervical  arteries  in  the  neck,  the 
intercostal  and  lumbar  below. 

What  are  the  ligaments  of  the  false  vertebrae  ? 

The  lig.  sacro-coccygenm  articalare  connects  the  cornua  of  the  sacrum 
and  coccyx.  The  lig.  sacro-coccygenm  ant.  is  the  analogue  of  the  ante- 
rior vertebral.  The  lateral  sacro-coccygeal  ligaments  correspond  to  the 
anterior  costo-transverse,  passing  from  the  lateral  edge  of  the  sacrum  to 
that  of  the  coccyx.  ^  The  deep  posterior  sacro-coccygeal  ligament  corre- 
sponds to  the  posterior  common,  and  receives  strengthening  bands  from 
the  dura  mater  of  the  cord.  The  superficial  sacro-coccygeal  closes  in  the 
lower  opening  of  the  spinal  canal,  passing  from  the  arch  of  the  last  sacral 
to  the  periosteum  of  the  coccyx.  This  ligament  may  split  below,  leaving 
a  median  cleft. 

Describe  the  articulations  of  the  rotation  vertebrae. 

The  ligaments  connecting  the  atlas  and  axis  are  two  anterior  atlo-axoid, 
the  posterior  atlo-axoid,  transverse,  and  two  capsular.     The  two  anterior 

7— A. 


98 


ARTICULATIONS   OF   THE   TRUNK   AND   HEAD. 


Fig.  6. 


atlo-axoid  (anterior  obturator)  comprise  a  superficial  rounded  cord  in  the 
median  line,  a  continuation  up  of  the  anterior  common  ligament  to  the 
occiput,  and  a  deeper  portion  on  either  side  from  the  anterior  arch  of 
the  atlas  to  the  base  of  the  odontoid  and  front  of  the  body  of  the  axis. 
In  front  of  them  are  the  recti  cap.  ant.  maj.  muscles. 

The  posterior  atlo-axoid  (posterior  obturator)  ligament  is  broad  and 
thin,  connecting  the  posterior  arches  of  the  two  bones  and  supplying  the 
place  of  the  ligamenta  subflava :  it  contains  a  little  elastic  tissue.  *  Behind 
it  are  the  inferior  oblique  muscles.  The  transverse  or  cruciform  ligament 
passes  across  the  ring  of  the  atlas  behind  the  odontoid.  It  holds  the 
odontoid  in  place,  but  not  with  such  firmness  as  often  described :  it  is 
broad  and  firm  in  the  middle,  and  in  it  is  often  developed  a  cartilaginous 
nodule ;  on  each  side  it  is  attached  to  the  lateral  mass  of  the  atlas.  A 
small  process  passes  up  (superior  crus)  from  its  upper  border  to  the  basi- 
lar process,  and  another  down  (inferior  crus)  to  the  root  of  the  odontoid 
posteriorly. 

The  capsular  ligaments  are  thin  and  loose,  strongest  in  front  and  ex- 
ternally :  there  is  also  a  capsule  for  the  anterior  odonto-atloid  articula- 
tion. The  synovial  membranes  are  four  in  number— one  for  each  capsular 
ligament,  one  for  the  anterior  articular  surface  of  the  odontoid,  and  one 
for  its  posterior  surface,  a  sort  of  bursa  which  may  communicate  with 

the  occipito-atloid  joints.  This  joint 
possesses  great  mobility,  the  greater 
part  of  the  rotation  of  the  head  oc- 
curring here,  and  none  in  the  occipito- 
atloid  joints.  ^  When  the  bones  are 
covered  by  articular  cartilage  a  sagittal 
section  shows  a  convexity  upon  a  con- 
vexity (Fig.  6).  With  the  head  equi- 
poised and  eyes  to  the  front  the  mus- 
cles are  at  rest  and  ligaments  tense. 
When  the  head  is  rotated  the  point  of 
the  atlas  sinks  down  off  the  axis  and 
a  part  projects ;  otherwise  an  already 
tense  ligament  would  become^  more 
tense  in  rotation,  did  not  the  points  of 
attachment  approach  each  other. 

The  spinal  column  is  connected  to 
the  cranium  by  ligaments  from  the 
occiput  to  the  atlas,  from  the  occiput  to  the  axis. 

Describe  the  articulations  of  the  occiput  and  atlas. 

There  are  two  anterior  occipito-altoid  ligaments  (anterior  obturator),  a 
posterior,  two  lateral,  and  two  capsular. 

The  supeiiicial  anterior  occipito-atloid  continues  the  anterior  common 
and  superficial  atlo-axoid  ligaments  upward  to  the  basilar  process.  The 
deep  ligament  is  thin,  and  passes  from  the  anterior  margin  of  the  fora- 


OCCIPUT-AXIS,   RIBS-VERTEBRiE.  99 

men  magnum  to  the  anterior  arch  of  the  atlas ;  behind  it  are  the  odon- 
toid ligaments. 

The  posterior  ocdpito-atloid  (posterior  obturator)  is  membranous  and 
blended  with  the  dura  mater  of  the  cord :  it  passes  from  the  posterior 
margin  of  the  foramen  magnum  to  the  posterior  arch  of  the  atlas.  Lat- 
erally, it  is  pierced  by  the  vertebral  artery  and  suboccipital  nerve. 

The  lateral  ligaments  are  fibrous  bands  passing  from  the  transverse 
processes  of  the  atlas  up  and  in  to  the  jugular  processes  of  the  occipital 
bone.  The  capsular  ligaments  are  loose,  and  enclose  a  synovial  mem- 
brane, which  usually  communicates  with  that  between  the  posterior  sur- 
face of  the  odontoid  and  transverse  ligament. 

The  movements  in  the  joint  are  flexion  and  extension,  a  nodding  move- 
ment through  about  45° :  there  is  a  slight  lateral  motion. 

Describe  the  ligaments  connecting  the  occiput  and  axis. 

There  are  the  occipito-axoid  and  three  odontoid.  ^  To  expose  these  the 
spinal  canal  must  be  opened.  The  occipito-axoid  hgament  prolongs  the 
posterior  common  ligament  to  the  front  of  the  foramen  magnum,  and 
there  blends  with  the  dura.  This  is  the  broad  ligament  of  the  axis  (lig. 
lata),  and  shows  three  sets  of  fibres :  the  posterior  blends  with  the  dura, 
the  next  is  the  continuation  of  the  posterior  common,  and  the  most  ante- 
rior or  deepest  set  is  confined  to  the  back  of  the  odontoid  and  body  of 
axis :  this  deepest  layer  also  joins  the  upper  part  of  the  posterior  surface 
of  the  transverse  ligament,  and  is  called  the  superior  appendix  of  the 
transverse  ligament.  A  bursa  is  often  between  this  broad  and  the  trans- 
verse ligament. 

From  either  side  of  the  apex  of  the  odontoid  process  an  alar  or  check 
ligament  passes  up  and  out  to  the  inner  side  of  the  condyle  of  the  occi- 
put. They  limit  the  extent  of  rotation.  From  the  apex  of  the  odon- 
toid a  middle  band  passes  to  the  front  of  the  foramen  magnum,  the 
"suspensory"  ligament,  but  it  suspends  nothing. 

Should  a  section  be  made  from  behind  forward  just  above  the  atlas, 
the  knife  would  divide  these  ligaments  in  order:  the  lig.  nuchas,  the 
posterior  occipito-atloid  (then  the  spinal  cord),  the  occipito-axoid,  the 
superior  crus  of  the  transverse,  the  odontoid,  the  deep  and  superficial 
anterior  occipito-atloid. 

Nerves  of  these  joints  are  from  the  suboccipital  and  second  cervical ; 
arteries  are  from  the  vertebral. 

Describe  the  ligaments  connecting  the  ribs  with  vertebrae. 

There  are  two  sets:  (1)  connects  heads  of  ribs  with  bodies;  (2)  con- 
nects necks  and  tubercles  with  transverse  processes. 

(1)  Anterior  costo-vertehral  or  stellate,  capsular^  inter  articular.  The 
stellate  consists  of  three  bundles  of  fibres  radiating  from  the  head  of  the 
rib :  the  upper  bundle  passes  to  the  vertebra  above,  the  lower  to  the 
vertebra  below,  and  the  middle  to  the  intervertebral  substance.  The 
first  rib  articulates  with  one  vertebra,  sends  up  a  slip  to  the  seventh  cer- 


100  ARTICULATIONS   OF   THE  TRUNK   AND   HEAD. 

vical,  a  middle  one  to  the  first  dorsal,  but  not  a  lower  one :  there  is  a 
similar  arrangement  with  the  eleventh  and  twelfth  ribs.  On  the  under 
edge  of  the  stellate  ligament  a  deep  fasciculus  passes  from  the  side  of 
the  body  to  the  under  surface  of  the  head  of  the  rib. 

The  stellate  ligament  is  continued  into  the  cervical  and  lumbar  regions  : 
a  slip  from  a  next  higher  vertebral  body  and  one  from  the  adjacent  in- 
tervertebral disk  or  body  run  to  the  root  of  the  transverse  process. 

The  capsular  ligament  is  a  loose  bag,  most  distinct  above  and  below, 
and  firmly  connected  with  the  stellate  ligament. 

The  interarticular  ligament  is  a  flat  horizontal  band  of  fibres  passing 
from  the  intervertebral  substance  to  the  crest  on  the  head  of  the  rib :  it 
divides  the  joint  into  non-communicating  cavities,  each  lined  by  a  sepa- 
rate synovial  membrane.  The  first,  eleventh,  and  twelfth  ribs  do  not 
possess  this  ligament. 

In  many  mammals  a  conjugal  ligament  unites  the  heads  of  opposite 
ribs  across  the  back  of  an  intervertebral  disk. 

(2)  Articulations  of  necks  and  tubercles  with  the  transverse  processes 
— superior^  middle  (interosseous),  and  posterior  costo-transverse  ligaments 
and  capsular. 

The  superior  ligaments  are  two  in  number :  the  anterior  passes  from 
the  upper  border  of  the  neck  of  each  rib  up  and  out  to  the  lower  border 
of  the  transverse  process  and  neck  of  rib  above.  Its  inner  border  com- 
pletes an  aperture  between  it  and  the  articular  process,  corresponding  to 
an  anterior  sacral  foramen.  Its  external  border  is  continued  in  a  thin 
aponeurosis  over  the  external  intercostal  muscle.  The  first  rib  does  not 
possess  this  ligament. 

The  posterior  band  is  less  regular,  and  extends  from  the  neck  of  the 
rib  up  and  in  to  the  transverse  and  lower  articular  process  next  above. 
^  The  middle  costo-transverse  is  very  short,  and  connects  the  neck  of  the 
rib  to  the  front  of  the  adjacent  transverse  and  articular  process.     This  is 
lacking  in  the  case  of  the  eleventh  and  twelfth  ribs. 

The  posterior  costo-transverse  passes  obliquely  from  the  summit  of  the 
transverse  process  to  the  tubercle  of  the  adjacent  rib  and  is  accessory  to 
the  capsule  behind — wanting  on  the  eleventh  and  twelfth  ribs.  The  joint 
has  a  thin  capsular  ligament  enclosing  a  synovial  membrane.  Nerves 
are  anterior  branches  of  spinal  nerves,  arteries  the  intercostals.  Action 
of  these  joints  is  elevation  and  depression  of  ribs  on  a  transverse  axis 
through  the  head  of  a  rib  and  its  articular  process — i.  e.  lengthwise 
through  its  neck :  there  are  also  eversion  and  inversion  of  ribs  on  an  axis 
connecting  their  sternal  and  vertebral  ends.  No  movement  on  a  vertical 
axis. 

HENLE»S   VERTEBRAL   AND   COSTAL  LIGAMENTS. 

A.  Synchondroses  and  capsular  ligaments.  Synchondroses  are  interverte- 
bral substances ;  capsular  are  three  sets :  (1)  for  articular  processes ;  (2)  for 
heads  of  ribs;  and  (3)  for  tubercles  of  ribs. 

B.  Accessory  ligaments — (1)  lig.  commune  vertebr.  ant. ;  (2)  ligg.  costo-ver- 
tebralia  radiata  (stellate). 


COSTAL   CARTILAGES   AND   STEENXTM. 


101 


C.  Ligaments  of  the  intertransverse  and  posterior  parts  of  tlie  intercostal 
spaces:  {a)  Ligg.  costo-transversaria :  (1)  antica,  (2)  postica.  The  anterior 
costo-transverse  is  that  of  Gray ;  the 

posterior  {ctp,  Fig.  7)  has  the  same  FiG.  7. 

origin  as  the  anterior ;  passes  up  and 
back  and  bifurcates,  the  inner  arm 
going  to  the  articular  process  above, 
the  lateral  arm  to  the  articular  and 
transverse  process  above.  Posterior 
vessels  and  nerves  pass  between  its 
insertions  and  beneath  its  free  edge. 
(6)  Ligg.  colli  costse — the  lig.  colli 
costse  sup.  and  lig.  c.  c.  inf.  form  the 
middle  costo-transverse  of  Gray.  Lig. 
colli  costse  posticum  passes  from  the 
neck  of  rib  near  the  head  through 
the  intervertebral  foramen  into  the 
spinal  canal  to  the  posterior  surface 
of  an  intervertebral  disk :  it  meets 
its  fellow  from  the  other  side  be- 
neath the  posterior  common  liga- 
ment— lig.  costarum  jugale  of  ani- 
mals, (c)  Ligg.  tuberculi  costse,  superior  and  inferior.  The  inferior  one  {tci, 
Fig.  7)  =  the  posterior  costo-transverse.  The  lig.  t.  c.  sup.  {tcs,  Fig.  7)  passes 
from  the  tubercle  of  one  rib  to  the  apex  of  the  transverse  process  next  above. 
(d)  Ligg.  tuberositatum  vertebralium  {tv,  Fig.  7)  =  intertransverse  of  Gray. 

The  last  internal  intercostal  muscle  sends  a  band  from  the  lower  edge  of 
the  eleventh  rib  down  to  the  twelfth,  often  to  the  twelfth  dorsal  vertebra ; 
similar  fibres  go  from  the  twelfth  rib  to  the  first  lumbar,  and  from  the  trans- 
verse process  of  the  first  lumbar  to  the  body  of  the  second :  it  is  the  acces- 
sory costo-vertebral  ligament  (stellate),  and  serves  for  muscular  origin,  espe- 
cially of  the  psoas. 

The  anterior  costo-transvere  ligaments  of  the  lower  intercostal  spaces  and 
two  upper  lumbar  vertebrae  unite  into  a  shining  aponeurosis,  the  lumbo-costal 
ligament.  It  passes  transversely  from  the  transverse  processes  of  the  two 
upper  lumbar  vertebrae  to  the  end  of  the  last  rib ;  thence  vertical  fibres  pass 
down  to  the  ilio-lumbar  ligament,  usually  behind  the  quadratus  lumborum 
•muscle. 

D.  Ligaments  of  the  spinal  canal.  (1)  Lig.  commune  verteb.  posticum ;  (2) 
ligamenta  intercruralia  =-  ligamenta  subflava. 

E.  Ligaments  of  spinous  processes,  ligg.  interspinalia,  lig.  supraspinale, 
and  lig.  nuchae. 

Describe  the  articulations  of  the  costal  cartilages  with  the  ster- 
num. 

Anterior  chondro-sfernal,  posterior  chondro-sternal,  and  capsular. 
The  anterior  one  is  a  broad,  radiating  band  with  superior,  middle,  and 
inferior  fascicuK.  They  intermingle  with  those  of  the  opposite  side  and 
with  the  origin  of  the  pectoralis  major,  forming  a  membrane  over  the 
sternum,  membrana  sterni.  The  posterior  chondro -sternal  hgaments  are 
less  distinct,  and  are  composed  of  radiating  fibres  blending  with  the  peri- 
osteum. The  capsular  ligaments  are  very  thin,  and  connected  with  the 
anterior  and  posterior  ones. 


102  ARTICULATIONS   OF  THE  TRUNK   AND   HEAD. 

Synovial  membranes^  the  first,  sixth,  and  seventh  cartilages,  have 
none  ;  the  third,  fourth,  and  fifth  have  one  ;  the  second  has  two  and  an 
interarticular  cartilage  resembling  a  vertebral  articulation.  In  old  age 
most  of  these  articulations  disappear. 

From  the  sixth  and  seventh  cartilages  chondro-xiphoid  (costo-xiphoid) 
ligaments  pass  down  and  in  to  the  ensiform,  strengthening  the  sheath  of 
the  rectus  and  limiting  the  aponeurosis  of  the  external  oblique. 

Describe  the  intercostal  ligaments. 

There  are  external  and  internal  intercostal  ligaments.  The  former, 
ligg.  intercostalia  ext. ,  lie  in  the  nine  or  ten  upper  spaces  between  the 
anterior  end  of  the  external  intercostal  muscle  and  the  sternum.  The 
fibres  are  partly  oblique,  vertical,  and  transverse.  The  vertical  and  ob- 
lique fibres  constitute  the  lig.  corruscans  (shining),  and  seem  to  be  un- 
developed bundles  of  the  external  intercostal  muscle  :  they  are  strongest 
in  the  third  to  the  seventh  spaces.  The  transverse  fibres  are  present  in  the 
first  to  the  seventh  spaces. 

The  internal  intercostal  ligameuts^  ligg.  intercostalia  int. ,  are  tendinous 
fasciculi  of  the  triangularis  sterni  muscle,  passing  from  rib  to  rib  over 
one  or  two  spaces :  in  the  seventh  and  eighth  spaces,  sometimes  sixth 
and  ninth,  they  are  nearly  transverse. 

Describe  the  interchondral  ligaments. 

The  cartilages  of  the  sixth,  seventh,  and  eighth  ribs,  sometimes  fifth  and 
ninth,  articulate  by  their  lower  borders  with  the  margins  of  the  adjoin- 
ing cartilage ;  each  articulation  has  a  capsule  and  synovial  membrane. 
All  these  articulations  may  be  wanting. 

In  articulations  of  ribs  with  cartilages  the  cartilage  is  held  in  a  de- 
pression in  the  sternal  end  of  the.  rib  by  periosteum. 

Describe  the  ligaments  of  the  sternum. 

The  gladiolus  is  united  to  the  manubrium  by  an  interposed  fibro-car- 
tilage,  synarthrodia!  (Henle),  or  it  may  be  diarthrodial  with  a  synovial 
membrane  in  33  per  cent,  of  cases — rarely  so  in  childhood — and  probably 
results  from  absorption.  The  ligaments  are  anterior  Midi  posterior  inter- 
sternal :  hoik  consist  of  longitudinal  fibres  blending  with  the  chondro- 
sternal  ligaments,  the  anterior  with  the  pectoralis  major. 

The  ligaments  of  the  hyoid  bone  will  be  described  with  those  of  the 
temporo-maxillary  articulation. 

What  are  the  ligaments  of  the  skull  ? 

(1)  The  petro-occipital  synchondrosis  possessed  originally  intervening 
hyaline  cartilage,  and  was  a  true  joint.  ( 2)  The  spheno-occipital  synchon- 
drosis contains  cartilaginous  nodules  ^  till  ossified  at  the  age  of  twenty- 
five.  The  soft  masses  of  connective  tissue  in  the  lacerated  foramen,  the 
petro-occipital  and  petro-sphenoidal  fissures,  are  known  as  ligaments  of 
the  same  names.  (3)  Accessory  hands,  a  number  of  ligamentous  bands 
bridging  over  grooves  and  bony  points,  completing  canals :  a  pterygo-pe- 


TEMPORO-M AXILLARY   ARTICULATION.  103 

trosal  ligament  from  the  upper  part  of  the  posterior  border  of  the  ex- 
ternal pterygoid  plate  to  the  spine  of  the  sphenoid,  sometimes  ossified  ; 
another  bridging  over  the  supraorbital  notch ;  an  intrajiigular  ligament 
dividing  the  jugular  foramen  ;  Sipetro-sphenoidal  ligament  from  the  apex 
of  the  petrous  to  the  posterior  clinoid  process  under  which  passes  the  sixth 
nerve.  A  lack  of  bone  between  the  foramen  ovale  and  spinosum  may 
be  supplied  by  ligament ;  the  clinoid  processes  of  one  side  may  be  con- 
nected by  ligament ;  one  may  pass  from  the  anterior  condylar  foramen 
to  the  jugular  notch  of  the  occipital. 

Describe  the  temporo-maxillary  articulation. 

The  ligaments  are — capsular^  interarticular  fihro-cartilage,  and  acces- 
sory^ which  include  external  lateral^  internal  lateral^  short  internal  lat- 
eral^ and  stylo-maxillary. 

The  capsule  is  very  thin  and  loose :  it  passes  from  the  edge  of  the 
glenoid  fossa  to  the  interarticular  cartilage,  thence  to  the  neck  of  the 
condyle. 

The  interarticular  dish  or  fihro-cartilage  is  placed  horizontally  between 
the  jaw  and  temporal  bone,  concavo-convex  above  and  concave  below.  It 
is  connected  in  front  with  the  external  pterygoid  muscle :  it  is  composed 
of  concentric  fibres ;  its  circumference  is  thick,  and  its  centre  may  be 
perforated. 

There  are  two  synovial  membranes  :  the  upper  is  the  larger  and  pro- 
longed in  front,  while  the  lower  is  smaller  and  prolonged  behind. 

The  external  lateral  ligament  (hg.  accessorium  laterale)  passes  from 
the  outer  surface  of  the  zygoma  and  tubercle,  their  lower  border,  down 
and  back  to  the  posterior  surface  of  the  neck  of  the  lower  jaw.  Exter- 
nally it  is  in  relation  with  the  temporal  fascia,  and  internally  with  the 
joint  capsule. 

The  interned  lateral  ligament  (lig.  acces.  mediaie)  has  two  parts :  one 
passes  from  the  inner  margin  of  the  glenoid  fossa  to  the  neck  of  the 
condyle  behind  the  insertion  of  the  external  pterygoid  muscle ;  this  is  in 
immediate  relation  to  the  capsule  and  known  as  the  short  internal  lateral 
ligament.  The  other  part  passes  from  the  spine  of  the  sphenoid  to  the 
lingula  and  inner  margin  of  the  dental  foramen  (spheno-maxillary).  Be- 
tween these  two  ligaments  are  the  internal  maxillary  artery  and  veins,  and 
lower  down  the  auriculo-temporal  and  inferior  dental  nerves ;  internal  to 
the  long  band  is  the  internal  pterygoid  muscle.  Between  the  short  in- 
ternal lateral  and  the  synovial  membrane  is  a  pad  of  soft  elastic  connective 
tissue  united  to  the  periosteum  of  the  posterior  half  of  the  glenoid 
fossa :  this  is  compressed  or  stretched  according  to  the  position  of  the 
condyle. 

The  stylo-maxillary  ligament  (stylo-mjdoid)  has  nothing  to  do  with 
this  articulation :  it  is  a  band  of  cervical  fascia  connected  at  one  end  by 
aid  of  the  stylo-glossus  muscle  to  the  styloid  process,  and  by  the  other 
to  the  angle  and  posterior  border  of  the  lower  jaw.  It  separates  the 
parotid  from  the  submaxillary  gland. 


104  ARTICULATIONS   OF  THE   UPPER   EXTREMITY. 

A  hyoid  ligament  may  be  described  here,  the  stylo-Tiyoid^  -wliicli  con- 
tinues the  styloid  process  down  to  the  lesser  cornu  of  the  hyoid  bone: 
it  is  often  ossified  in  man,  and  usually  is  in  many  animals,  as  the  epihyal 
hone. 

The  pterygo-maxillai'y  ligament  passes  from  the  apex  of  the  internal 
pterygoid  plate  to  the  posterior  extremity  of  the  internal  oblique  line  of 
the  lower  jaw :  it  separates  the  buccinator  from  the  superior  constrictor 
of  the  pharynx. 

Origin.  Insertion. 

Splieno-maxillary  ligament,  spine  of  sphenoid.    Dental  foramen. 
Pterygo-       "  "         int.  pterygoid  plate.  Alveolar  border  of  lower  jaw. 

Stylo-  "  "         styloid  process.  Angle  lower  jaw. 

Stylo-hyoid  "  "  "  Lesser  cornu  of  hyoid  bone. 

Nerves  of  the  joint  are  the  auriculo-temporal  and  masseteric  from  the 
inferior  maxillary.  Arteries  are  temporal,  the  deep  auricular,  and  tym- 
panic branches  of  the  internal  maxillary.  Actions  of  the  joint  are  protru- 
sion and  retraction,  elevation  and  depression,  or  a  rotation  when  one  side 
acts.  The  movements  in  the  superior  and  inferior  compartments  are  of 
different  kinds :  in  the  upper  the  fibro-cartilage  glides  forward  and  back- 
ward, and  in  the  lower  the  condyle  rotates  against  it  on  a  transverse  axis. 
Elevation  and  depression  take  place  on  a  transverse  axis  through  the  cen- 
tres of  the  rami — some  say  through  the  interarticular  cartilages.  If  the 
depression  be  considerable,  the  condyle  also  has  a  gliding  motion,  carrying 
the  cartilage  with  it.  Rotary  movement  to  one  or  other  side  takes  place 
on  an  axis  through  the  opposite  condyle.  Depression  is  produced  by 
the  weight  of  the  jaw,  platysma,  digastric,  mylo-hyoid,  and  genio-hyoid 
muscles ;  elevation  by  the  temporal,  masseter,  and  internal  pterygoid ; 
protrusion  by  external  pterygoid,  internal  pterygoid,  and  superficial 
fibres  of  masseter ;  retraction  by  deep  fibres  of  masseter  and  posterior 
fibres  of  temporal. 

ARTICULATIONS  OP  THE  UPPER  EXTREMITY. 

THE   SHOULDER  GIRDLE. 
What  are  the  proper  ligaments  of  the  scapula  ? 

Coraco-acromial^  superior  and  inferior  transverse,  and  glenoid. 

The  coraco-acromial  ligament  is  a  thin  triangular  band  attached  by  its 
apex  to  the  summit  of  the  acromion  in  front  of  and  beneath  the  clavic- 
ular articulation,  and  by  its  base  to  the  whole  length  of  the  outer  border 
of  the  coracoid  process :  it  completes  a  vault  for  the  protection  of  the 
head  of  the  humerus.  Above  it  is  the  deltoid,  and  below  it  the  supra- 
spinatus  muscle.  The  subacromial  bursa  separates  it  above  from  the 
acromion  and  acromial  end  of  clavicle,  and  below  the  bursa  covers  the 
capsule  over  the  head  of  the  humerus  and  spreads  out  between  the  in- 
fraspinatus and  supraspinatus  muscles. 


THE  SHOULDER   GIRDLE. 


105 


The  superior  transverse  ligament  (suprascapular)  is  a  flat  shining  band 
passing  between  the  inner  margin  of  the  scapular  notch  and  the  root  of 
the  coracoid.     As  a  rule  it  has  two  parts  (t.  s.,  Fig.  8) — an  upper,  longer 

Fig.  8. 


Ligaments  of  Scapula. 


and  stronger  and  lying  in  a  plane  with  the  surfaces  of  the  supraspinous 
fossa  and  somewhat  oblique ;  a  lower  part,  thin,  horizontal,  and  more 
anterior  than  the  upper.  Above  the  ligament  are  the  suprascapular 
artery  and  one  of  its  venae  comites ;  between  the  two  parts  are  the  supra- 
scapular nerve  and  the  other  suprascapular  vein ;  beneath  the  lower  arm 
of  the  ligament  are  two  veins  passing  to  a  venous  plexus  in  the  sub- 
scapular fossa. 

The  inferior  transverse  ligament  (t.  I. )  (spino-glenoid)  is  in  the  great 
scapular  notch,  and  passes  from  the  base  of  the  spine  of  the  scapula  to 
the  posterior  surface  of  the  head  of  the  scapula.  This  may  be  a  feeble 
band  of  fatty  tissue  or  a  strong  one  of  connective  tissue :  beneath  it 
anastomotic  vessels  run  from  one  spinous  fossa  to  the  other.  The 
glenoid  ligament  will  be  described  with  the  shoulder-joint. 

Describe  the  sterno-clavicular  ligaments. 

The  ligaments  are  capsular  ^^  inter  articular  jihro-cartilage ;  accessory  are 
interclavicular  and  costo-claviculav. 

Henle  describes  a  capsule  for  this  joint  made  up  mostly  of  strengthen- 
ing bands :  it  is  weakest  at  the  lower  anterior  angle.  In  front  a  band 
called  the  anterior  sterno-clavicular  ligament  passes  from  the  inner  ex- 


106  ARTICULATIONS   OF   THE   UPPER   EXTREMITY. 

tremity  of  the  clavicle  obliquely  down  and  in  to  the  upper  part  of  the 
manubrium ;  the  post,  sterno-dav.  lig.  passes  in  a  similar  direction,  and 
is  related  behind  with  the  sterno-thyroid  and  sterno-hyoid  muscles. 

The  interarttcular  cartilage  is  attached  above  to  the  upper  and  poste- 
rior border  of  the  inner  extremity  of  the  clavicle,  and  below  to  the  junc- 
tion of  the  first  costal  cartilage  with  the  sternum,  and  by  its  circumfer- 
ence to  the  capsule :  thus  the  cartilage  of  the  first  rib  is  partly  within 
this  joint.  Its  circumference  is  thicker  than  its  centre,  which  may  be 
perforated :  in  size  and  shape  it  varies  greatly.  It  lessens  the  inequal- 
ities of  the  two  bony  surfaces,  and  divides  the  joint  into  two  parts,  each 
provided  with  a  synovial  membrane.  In  young  bones  the  interclavicular 
notch  on  the  sternum  is  covered  with  hyaline  cartilage. 

The  interclavicular  ligament  is  a  flat  band  passing  in  a  curved  direc- 
tion between  the  inner  extremities  of  the  clavicles,  and  is  closely  attached 
to  the  upper  border  of  the  sternum.  Some  of  its  fibres  are  connected 
with  the  periosteum  of  the  posterior  surface  of  the  sternal  end  of  the 
clavicle,  and  some  with  the  back  of  the  capsule.  So  if  we  follow  the 
course  of  the  connective  tissue  from  the  upper  border  of  the  clavicle, 
some  goes  to  the  interarticular  cartilage,  some  to  the  capsule,  and  some 
forms  the  interclavicular  ligament. 

The  costo-clavicular  ligament  is  of  rhomboid  form,  ascending  obliquely 
from  the  inner  part  of  the  cartilage  of  the  first  rib  back  to  the  depression 
on  the  under  surface  of  the  sternal  end  of  the  clavicle.  To  its  outer  side 
is  the  subclavian  vein.  This  ligament  encloses  the  tendon  of  insertion 
of  the  subclavius  muscle,  but  most  of  the  ligament  is  behind  the  muscle, 
its  anterior  part  being  continued  as  fascia  over  it.  Between  the  muscle 
and  the  posterior  part  of  the  ligament  is  sometimes  developed  the 
' '  bursa  of  Monro. ' '  Cruveilhier  describes  this  ligament  and  bursa  as 
the  costo-clavicular  articulation. 

Nerves,  second  and  third  cervical  by  descendens  noni.  Arteries^  neigh- 
boring muscular  branches.  Motion  is  not  a  gliding,  but  axial  on  the 
fibro-cartilage.  Elevation  and  depression  of  the  shoulder  produce  move- 
ment here  on  a  transverse  axis  through  the  costo-clavicular  ligament; 
movement  of  shoulder  forward  or  backward,  on  a  vertical  axis  through 
the  same  point. 

Describe  the  acromio-clavicular  ligaments. 

Ligaments  are  capsular^  intei^articular  Jibro-cartilage ;  accessory  are 
posterior  coraco-clavicular  or  trapezoid  and  conoid^  and  anterior  coraco- 
clavicular. 

There  is  a  weak  capsule  to  this  joint,  really  a  fibrous  covering  of  the 
synovial  membrane :  it  is  strongest  above,  being  strengthened  above  and 
below  by  bands  designated  by  some  as  the  superior  and  inferior  acromio- 
clavicidar  ligaments.  The  interarticular  cartilage  is  usually  present  in 
some  form,  either  hanging  from  the  edge  of  the  clavicle  in  the  upper 
part  of  the  joint  or  covering  the  whole  articular  surface  of  the  acromion, 
or  in  3  out  of  400  cases  wholly  dividing  the  joint  into  two  cavities. 


THE   SHOULDER   GIRDLE.  107 

The  synovial  membrane  is  usually  single,  or  double  when  the  inter- 
articular  cartilage  is  complete. 

The  coraco-daviciilar  ligaments  connect  the  clavicle  more  firmly  with 
the  scapula :  there  are  three.  The  posterior  coraco-clavicular  comprises 
the  trapezoid  and  conoid.  The  trapezoid  is  external,  and  attached  below 
to  the  upper  surface  of  the  coracoid,  and  above  to  the  oblique  line  pass- 
ing forward  and  outward  on  the  under  surface  of  the  clavicle.  Its  outer 
border  is  free,  and  its  internal  border  unites  with  the  conoid,  forming  an 
angle  projecting  backward.  This  checks  forward  movement  of  the 
clavicle. 

The  conoid  is  posterior  and  internal,  and  attached  by  its  apex  to  the 
base  of  the  coracoid,  and  by  an  expanded  base  to  the  conoid  tubercle 
and  a  line  internal  to  it  on  the  under  surface  of  the  clavicle.  This  checks 
backward  movement  of  the  clavicle.  Between  these  two  ligaments  a 
bursa  may  be  developed,  and  between  them  is  also  the  extremity  of  the 
subclavius  muscle. 

The  anterior  coraco-clavicfular  ligament  (Henle)  is  a  shining  thin  band 
of  connective  tissue  passing  from  the  apex  of  the  coracoid  up  and  into 
the  under  surface  of  the  clavicle.  At  its  origin  it  is  connected  with  the 
fascia  over  the  pectoralis  minor,  and  at  its  insertion  with  the  fascia  over 
the  subclavius,  from  which  it  is  separated  in  part  by  a  layer  of  fatty 
tissue. 

An  occasional  scapulo-clavicular  ligament  has  been  described  passing 
from  the  upper  border  of  the  scapula  internal  to  the  notch  to  the  acro- 
mial end  of  the  clavicle. 

Nerves,  suprascapular  and  circumflex.  Arteries ,  suprascapular  and 
acromial  thoracic.     Movements  of  joint,  gliding  and  rotation. 

Describe  the  ligaments  of  the  shoulder-joint. 

The  ligaments  are,  capsular,  glenoid,  coraco-humeral,  coraco-glenoid, 
transverse  humeral,  glenoideo-humeral  or  Flood's^  and  the  glenoideo- 
brachial  internal  and  inferior  of  Schlemm. 

The  strengthening  bands  are  parts  of  the  capsule,  and  not  accessory 
ligaments  so  called. 

This  is  a  ball-and-socket  joint,  peculiar  (1 )  in  the  large  size  of  the  head 
of  the  humerus  aud  shallowness  of  the  glenoid  cavity ;  (2)  looseness  of 
the  capsule ;  (3)  intimate  relation  of  muscles  with  capsule ;  (4)  relation 
of  biceps  tendon  to  joint.  The  glenoid  articular  cartilage  is  thinnest  at 
its  centre,  ^V  inch  (1  mm. ) ;  that  on  the  head  of  the  humerus  is  thickest 
at  the  centre,  ^  inch  (2  mm. ). 

The  capsule  encircles  the  articulation,  attached  above  to  the  margin  of 
the  glenoid  beyond  the  glenoid  ligament,  and  below  to  the  anatomical 
neck  of  the  humerus.  It  allows  the  bones  to  be  separated  more  than  an 
inch :  it  is  strengthened  by  tendons  of  muscles  which  may  be  reck- 
oned as  ligaments— viz.  above  by  the  supraspinatus  and  tendon  of  biceps, 
externally  by  the  infraspinatus  and  teres  minor,  below  by  the  long  head 
of  the  triceps,  and  internally  by  the  subscapularis.     There  is  a  weak 


108 


ARTICULATIONS   OF  THE   UPPER   EXTREMITY. 


place  in  the  capsule  uncovered  by  muscle  between  the  edges  of  the  teres 
major  and  subscapularis ;  vessels  and  nerves  enter  here  (Al,  Fig.  9). 

The  superficial  fibres  of  the  capsule  are  longitudinal,  and  deeper  ones 
are  circular,  forming  a  truncated  cone  with  its  narrow  end  toward  the 
scapula.  Below  are  folds  in  the  capsule  which  become  straight  in  raising 
the  arm. 

The  glenoid  ligament  is  a  fibro-cartilaginous  rim  attached  to  the  mar- 
gin of  the  glenoid  fossa  to  form  a  deeper  cavity :  it  is  triangular  on  sec- 
tion ,  and  -i^  inch  (3  mm. )  broad  at  its  base.  It  is  partly  formed  by  the  biceps . 
tendon  above  as  it  bifurcates  at  its  attachment,  and  by  the  triceps  below, 
the  fibres  being  arranged  in  concentric  rings.  Its  intrinsic  fibres  are 
fused  with  the  capsule. 

The  synovial  membrane  lines  the  capsule  and  covers  the  outer  side  of 

Fig.  9. 


Left  Shoulder-joint  opened  from  Behind  and  Externally :  1,  thickening  of  supraspinatus 
tendon ;  B,  biceps  tendon  ;  2,  glenoideo-humeral,  or  Flood's  lig. ;  3,  thickening  of  sub- 
scapular tendon;  *  *,  entrance  to  the  subscapular  bursa ;  4,  inf.  glenoideo-brachial  of 
Schlemm,  between  4  and  3,  int.  glenoideo-brachial  of  Schlenim  ;  *  glenoid  cavity ;  X  cut 
surface  of  humerus ;  Isp,  infraspinatus  ;  2Vw,  teres  minor ;  Tmj^  teres  major;  Al^  circum- 
flex vessels;  Ab,  short  head  of  triceps. 

the  glenoid  ligament,  and  is  continued  a  short  distance  over  the  cartilage 
on  the  head  of  the  humerus.  The  long  tendon  of  the  biceps  passing 
through  the  capsule  is  enclosed  in  a  tubular  sheath  of  synovial  mem- 


THE  SHOULDER   GIRDLE.  109 

brane,  and  so  does  not  really  enter  the  synovial  cavity.  A  rounded  pro- 
trusion of  synovial  membrane,  biirsa  inter  tuber  cularis^  clothes  the  upper 
part  of  the  bicipital  groove  as  far  as  the  insertion  of  the  pect.  major  and 
latiss.  dorsi.  From  within  the  tube  of  synovial  membrane  there  passes 
to  the  tendon  of  the  biceps  a  retinaculum  of  longitudinal  bundles  of 
connective  tissue. 

Among  the  strengthening  bands  of  the  capsule  is  the  coraco-humeral 
ligament^  rising  from  the  outer  border  of  the  coracoid,  spreading  out 
upon  the  upper  and  posterior  wall  of  the  capsule,  and  inserted  into  the 
great  tuberosity  of  the  humerus.  The  transverse  himieral  ligament  is  a 
part  of  the  capsule  between  the  tuberosities.  The  lig.  coraco-glenoidale 
is  a  part  of  the  coraco-humeral,  rising  with  it  and  passing  backward  and 
outward  at  right  angles  from  it  on  the  surface  of  the  capsule  to  the  upper 
margin  of  the  glenoid  cavity.  When  the  joint  is  viewed  from  the  inside 
(Fig.  9),  the  glenoideorhumeral,  or  Flood's  Hgament,  is  seen  as  a  reflec- 
tion of  the  fibres  of  the  coraco-humeral  ligament  through  the  capsular 
opening,  passing  up  internal  to  the  tendon  of  the  biceps. 

The  internal  glenoideo-hrachial  ligament  of  Schlemm  is  a  thin  fold 
rising  from  a  point  above  the  entrance  into  the  subscapular  bursa,  and, 
descending  obhquely  outward  to  be  lost  on  the  capsule  beneath  the  sub- 
scapular tendon  (is  between  (3)  and  (4)  in  Fig.  9),  passes  to  the  small 
tuberosity  (Quain).  The  lig.  glenoideo-hrachiale  inf.^  or  broad  ligament 
of  Schlemm  (4),  rises  from  the  upper  part  of  the  glenoid  ligament  and 
passes  down  and  out  parallel  to  the  internal  lig.  of  Schlemm,  and  is  lost 
on  the  circular  fibres  of  the  inner  capsular  wall. 

Quain  calls  the  three  ligaments  last  described  the  superior,  middle, 
and  inferior  gleno-humeral  ligaments. 

What  holds  the  head  of  the  humerus  in  place  ? 

(1)  Subscapular,  supraspinatus,  infraspinatus,  deltoid,  biceps,  and  tri- 
ceps muscles;  (2)  adhesiveness;  (3)  atmospheric  pressure. 

What  are  the  communications  of  the  joint  ? 

Subscapular,  infraspinatus  bursse,  biceps  tendon,  often  the  subcoracoid, 
coracoid,  subacromial,  and  subdeltoid  bursae. 

The  nerves  supplying  the  joint  are  circumflex  and  suprascapular. 

The  arteries  are  anterior  and  posterior  circumflex  and  suprascapular. 

The  movements  of  the  joint  are  in  every  direction. 

Flexion  is  possible  to  45°  without  involving  other  joints,  produced  by 
the  pectorahs  major,  anterior  fibres  of  the  deltoid,  coraco-brachialis,  and 
by  the  biceps  if  the  elbow  is  fixed.  This  occurs  on  a  transverse  axis 
through  the  great  tuberosity  and  glenoid  cavity.  Flexion  is  limited  by 
tension  of  the  posterior  part  of  the  capsule  and  by  the  small  tuberosity 
abutting  against  the  coracoid ;  the  movement  is  continued  by  rotation  of 
the  scapula. 

Extension  through  15°  is  produced  by  the  latissimus  dorsi,  teres  major, 
posterior  fibres  of  deltoid,  and  the  triceps  if  the  elbow  is  fixed.     Exten- 


110  ARTICULATIONS   OF  THE   UPPER   EXTREMITY. 

sion  is  hindered  by  superior  muscles  and  approximation  of  the  great 
tuberosity  and  acromion. 

Abduction  through  90°  is  performed  by  the  deltoid,  aided  by  the 
supraspinatus,  on  an  antero-posterior  axis  through  the  anatomical  neck 
of  the  humerus :  further  motion  calls  into  play  accessory  joints — viz. 
the  upper  portion  of  the  trapezius  elevates  the  peak  of  the  shoulder, 
and  the  lower  fibres  of  the  serratus  magnus  pull  the  inferior  angle  of 
the  scapula  forward,  rotating  that  bone,  which  raises  its  external  angle. 
Two  other  joints  share  the  motion — the  acromio-clavicular  till  its  yield- 
ing is  stopped  by  the  coraco-clavicular  ligaments,  next  the  sterno-clavic- 
ular  joint  till  its  motion  is  checked  by  the  costo-clavicular  ligament.  So 
three  chief  muscles  are  concerned  in  raising  the  hand  above  the  head, 
and  two  joints  besides  the  shoulder-joint.  Freest  motion  is  up  and  for- 
ward. The  angle  between  the  scapula  and  clavicle  changes  to  secure 
adaptation  of  the  former  to  the  chest-wall. 

Adduction  is  accomplished  by  the  subscapularis,  pectoralis  major, 
latissimus  dorsi,  and  teres  major.  Total  rotation  is  through  90°,  limited 
by  capsule  and  muscles :  it  is  freest  externally  and  backward  ;  rotation 
in  is  produced  by  the  subscapularis,  latissimus  dorsi,  and  teres  major ; 
rotation  out  by  the  infraspinatus  and  teres  minor.  Circumduction  is  a 
combination  of  all  the  angular  movements  in  succession. 

THE  BLBO'W  AND  FOREARM. 
Describe  the  elbow-joint. 

The  elbow  is  a  hinge  joint  with  screw-like  surfaces :  really  three  joints 
are  involved,  the  ginglymus  screw,  the  radio-humeral,  and  the  radio- 
ulnar. The  lesser  sigmoid  of  the  ulna  and  the  articular  surface  of  the 
radius  are  parts  of  cylindrical  surfaces,  the  latter  an  arc  of  1 80°,  the 
former  of  90°  and  radius  of  i  inch  (12  mm. ).  The  diameter  of  the  curve 
on  the  humerus  at  the  inner  edge  of  the  trochlea  is  16  mm. ,  of  the  groove 
of  the  trochlea  1 1  mm. ,  of  the  outer  edge  of  the  trochlea  1 3  mm. ,  and  of 
the  capitellum  12  mm.  The  articular  cartilage  in  the  elbow-joint  is 
hyaline  and  2  mm.  thick.  Only  so  much  of  the  trochlea  is  covered  by 
cartilage  as  is  embraced  by  the  sigmoid  cavity  when  the  forearm  is  flexed 
to  90° :  the  parts  remaining  free,  anteriorly  and  posteriorly,  are  covered 
with  periosteum  and  fatty  pads.^ 

The  ligaments  are  capsular,  with  thickened  bands  and  the  orhicidar 
ligament;  the  thickened  bands  are  known  as  an^mor  and  posterior^  in- 
ternal lateral  and  external  lateral.  The  radial  insertion  of  the  capsule 
is  the  orbicular  ligament  surrounding  the  head  of  the  radius  ;  the  cap- 
sule includes  the  coronoid  and  part  of  the  olecranon  fossae,  a  part  of  the 
internal  epicondyle,  but  not  the  external,  the  tips  of  the  coronoid  and 
olecranon  processes. 

The  anterior  thickened  portion  of  the  capsule  passes  from  the  point  of 
the  inner  epicondyle  and  from  the  front  of  the  humerus  above  the  coronoid 
fossa  to  the  anterior  margins  of  the  coronoid  process,  and  externally  into 


PLATE  VII. 
Fig.  1. — To  face  page  111. 


Ijeft  Elbow-joint,  showing  anterior  and  internal  ligaments. 


PLATE  VIII. 

Fig.  1,— To  face  page  111. 


Left  Elbow-joint,  showing  posterior  and  external  ligaments. 


THE   ELBOW   AND    FOREAKM.  Ill 

the  orbicular  ligament.  Superficially  is  an  oblique  band  passing  down  and 
out  from  the  internal  epicond.yle  to  the  orbicular  ligament.  The  fibres 
under  these  are  vertical,  the  anterior  ligament  of  Barkow^  and  the  deepest 
are  transverse.  The  posteinor  part  of  the  capsule  passes  to  the  margin 
of  the  olecranon  process  from  the  lower  end  of  the  humerus,  leaving  the 
upper  part  of  the  fossa  exposed.  The  lowest  fibres  are  transverse,  bridging 
over  part  of  the  olecranon  fossa ;  the  upper  fibres  are  vertical,  thickest 
in  the  median  line,  and  pass  through  a  fatty  pad  in  the  upper  part  of 
the  fossa.  These  vertical  fibres  are  Barkowis  posterior  straight  cubital 
ligament :  on  either  side  of  it  the  capsule  is  as  thin  as  a  bursa. 

The  internal  lateral  ligament  is  fan-shaped,  rises  from  the  lower  and 
back  part  of  the  root  of  the  inner  epicondyle,  and  consists  of  three  por- 
tions: (I)  a  posterior  humero-olecranon  part,  helping  form  the  groove 
for  the  ulnar  nerve;  (2)  an  anterior  humero-coronoid  psirt ]  and  (3)  an 
olecrano-coronoid  portion,  deepening  the  sigmoid  cavity. 

The  external  lateral  ligament  is  not  so  distinct  as  the  internal,  is  at- 
tached above  to  a  depression  below  the  external  epicondyle,  and  below  to 
the  orbicular  ligament  and  posterior  interosseous  border  of  the  ulna  (not 
into  the  radius,  or  its  rotation  would  be  impaired).  It  gives  some  strength- 
ening bands  to  the  anterior  ligament,  forming  a  cruciform  arrangement. 
The  supinator  brevis  rises  from  this  ligament  in  part.  The  brachialis 
anticus  muscle  inserts  a  band  into  the  anterior  ligament,  the  triceps  a 
band  into  the  posterior.  The  anconeus  rises  from  the  capsule  between 
the  external  condyle  and  external  border  of  the  olecranon. 

The  orbicular  ligament ^  lig.  annulare  radii,  is  the  thickest  part  of,  and 
is  the  inferior  radial  edge  of,  the  capsular.  ^  It  is  f  inch  ( 1 0  mm. )  broad, 
and  is  the  only  ligament  of  the  superior  radio-ulnar  articulation  which  is  a 
lateral  ginglymus  joint.  ^  The  ligament  is  attached  by  each  end  to  the  ex- 
tremities of  the  small  sigmoid  cavity,  surrounds  the  head  of  the  radius, 
forming  four-fifths  of  a  circle.  It  is  broader  in  the  upper  part  of  the  cir- 
cumference than  below,  grasping  the  head  of  the  radius  more  firmly. 
The  supinator  brevis,  extens.  carpi  uln.,  extens.  min.  dig.,  and  extens. 
com.  dig.  rise  in  part  from  the  orbicular  ligament. 

The  synovial  membrane  is  extensive,  lines  the  capsule  and  orbicular 
ligament,  entering  into  the  articulation  between  all  three  bones. 

There  are  inequalities  between  the  sigmoid  fossa  and  trochlea  which 
are  filled  in  with  synovial  membrane  or  fatty  pads :  there  is  another  pad 
in  the  small  sigmoid  cavity.  The  capsule  is  reinforced  by  intra-  and  ex- 
tracapsular pads,  both  in  the  coronoid  and  olecranon  fossae.  This  allows 
free  gliding  of  muscles.  The  triceps  pulls  up  the  wrinkled  capsule  in 
extension,  the  brachialis  anticus  in  flexion. 

The  muscles  in  relation  to  J:he  joint  are,  in  front,  the  brachialis  anti- 
cus ;  behind,  the  triceps  and  anconeus ;  externally,  the  supinator  brevis 
and  supinato-extensor  group ;  internally,  the  pronato-flexor  group. 

What  bursse  are  related  to  the  joint  ? 

(1)  Superficial  olecranon  between  tendon  of  triceps  and  skin;  (2)  deep 


112  ARTICULATIONS   OF   THE   UPPER   EXTREMITY. 

olecranon,  between  tendon  of  triceps  and  bone ;  (3)  at  inner  margin  of 
brachialis  anticus;  (4)  bicipital  bursa,  between  tendon  of  biceps  and 
bone;  (5)  epicondylar  bursae,  subcutaneous;  (6)  sometimes  a.  retro-epi- 
trochlear  behind  the  inner  epicondyle,  related  to  the  ulnar  nerve. 

Nerves  are  from  the  ulnar,  median,  musculo-spiral,  internal  cutaneous, 
and  nerve  of  Cruveilhier  (from  the  branch  of  the  musculo-cutaneous  to 
the  biceps). 

Arteries  are  derived  from  an  anastomosis  between  the  inferior  and  su- 
perior profunda,  anastomotica  magna,  anterior  and  posterior  ulnar  recur- 
rent, interosseous  recurrent,  and  radial  recurrent. 

Action. — The  humero-ulnar  joint  possesses  flexion  and  extension,  no 
lateral  movement  or  rotation. 

Flexion  of  150°  is  possible,  produced  hy  the  supinator  longus,  biceps, 
brachialis  anticus,  and  muscles  from  the  inner  condyle  :  it  is  checked  by 
contact  of  soft  parts,  posterior  part  of  capsule,  and  posterior  part  of  in- 
ternal and  external  lateral  ligaments,  not  by  bone. 

Extension  (after  flexion)  goes  through  150°  by  the  triceps,  anconeus, 
extensors  of  the  wrist,  and  common  extensors  of  fingers :  it  is  checked 
by  the  anterior  part  of  the  capsule  and  anterior  parts  of  the  external 
and  internal  lateral  ligaments,  not  by  bone. 

Supination  (rotation  out)  and  pronatio7i  (rotation  in)  occur  through 
90°  in  the  radio-ulnar  and  radio-humeral  joints  on  an  axis  through  the 
head  and  neck  of  the  radius  and  stjdoid  process  of  the  ulna.  Supina- 
tion is  performed  by  the  biceps  strongly,  by  the  supinator  longus  and 
brevis  and  extensors  of  the  thumb ;  pronation  by  the  pronator  radii  teres 
and  pronator  quadratus:  in  this  last  motion  there  is  a  "winding  up'.' 
of  the  biceps  and  supinator  brevis.  These  rotary  movements  are 
checked  by  the  oblique  ligament,  orbicular,  and  capsular,  by  the  inter- 
osseous membrane,  by  the  inferior  articulation,  and  by  muscles.  If 
sliding  of  soft  parts  on  the  ulna  is  hindered,  pronation  and  supination 
are  largely  checked. 

Experiment. — ^Thrust  the  hand  pronated  through  a  round  hole  in  a 
board :  if  it  be  the  right  hand,  mark  on  the  board  the  position  of  the 
styloid  process  of  the  ulna,  as  at  a.  ^  Supi- 
nate  the  hand,  and  the  ulnar  styloid  pro- 
cess will  be  found  at  h. 

What  is  the  explanation  if  the  ulna  has 
no  lateral  motion  ? 
The  first  movement  back  from  a  is  of  ex- 
tension, which  occurs  at  the  elbow-joint; 
the  next,  near  c,  is  adduction,  and  occurs 
at  the  shoulder- joint;  the  final  movement 
to  b  is  flexion  at  the  elbow.  When  ro- 
tated back  again  we  have  extension,  abduction,  and  flexion  in  order. 
If  now  the  humerus  be  firmly  fixed  as  in  a  vice,  so  as  to  prevent 
ad-  and   abduction  at  the  shoulder-joint,  the  styloid  of  the  ulna  will 


THE  WRIST   AND   CARPUS.  113 

not  change  position,  and  the  experiment  could  not  be  done  in  the  above 
aperture. 

Describe  the  accessory  ligaments  of  the  bones  of  the  forearm. 

(1)  Oblique;  (2)  interosseous.  The  oblique  ligament  (chorda  trans- 
versaHs)  is  a  flatly-rounded  cord  running  from  the  tubercle  of  the  ulna 
on  the  coronoid  process  down  and  out  to  a  point  on  the  radius  a  little 
below  the  bicipital  tuberosity.  Its  fibres  have  an  opposite  direction  to 
those  of  the  interosseous  ligament.  The  oblique  may  be  wanting,  or  may 
exist  as  a  tendinous  slip  to  the  flexor  long.  poll.  ;  it  may  be  double,  the 
upper  band  passing  from  the  small  sigmoid  notch  and  orbicular  ligament 
to  a  point  above  the  bicipital  tuberosity. 

The  interosseous  ligament  (membrane)  connects  the  interosseous  ridges 
of  the  radius  and  ulna.  The  fibres  pass  down  and  in  to  the  ulna  in  such 
a  direction  that  if  the  hand  press  against  resistance  the  radius  would 
drag  the  ulna  after  it.  The  ligament  is  divisible  here  and  there  into  sev- 
eral layers,  some  fibres  coming  from  the  anterior  surface  of  the  radius. 
It  is  deficient  above,  commencing  on  the  radius  at  the  insertion  of  the 
oblique  ligament,  leaving  a  space  between  the  two  for  the  posterior  in- 
terosseous vessels.  Just  above  its  lower  end  is  an  oblique  opening  be- 
tween two  layers  of  the  ligament  for  the  passage  of  the  anterior  interos- 
seous vessels.  The  lower  edge  is  almost  vertical,  the  fibres  ending  higher 
on  the  ulna  than  on  the  radius  and  running  in  a  direction  opposite  to  the 
fibres  above :  this  lowest  split  between  the  ligament  and  ulna  is  filled 
with  fat  and  covered  by  the  pronator  quadratus  muscle.  Some  fibres  go 
to  the  posterior  annular  ligament.  The  object  of  the  ligament  is  mus- 
cular attachment  with  economy  of  weight. 

Describe  the  inferior  radio-ulnar  articulation. 

A  lateral  ginglymus  joint  between  the  head  of  the  ulna  and  sigmoid 
cavity  of  the  radius.  The  ligaments  are  the  anterior  and  posterior  radio- 
ulnar and  triangular  Jibro-cartilage.  The  anterior  and  posterior  liga- 
ments are  narrow  bands  passing  transversely  over  the  joint,  as  indicated 
by  their  names.  The  triangular  ligament  is  placed  beneath  the  ulna, 
attached  by  its  apex  to  the  base  of  the  styloid  process ;  its  under  surface 
articulates  with  the  cuneiform.  The  synovial  membrane  is  very  exten- 
sive, the  meinbrana  sacciformis. 

Actions  are  supination  and  pronation. 

THE  •WRIST  AND  CARPUS. 
Describe  the  radio-carpal  or  wrist-joint. 

This  is  a  condyloid  articulation  between  the  radius  and  triangular  car- 
tilao^e  above,  the  scaphoid,  semilunar,  and  cuneiform  below. 

The  ligaments  are  external  and  internal  lateral^  anterior^  and  poste- 
rior. The  two  former  are  rounded  cords  passing  respectively  from  the 
styloid  process  of  the  radius  and  ulna  to  the  end  carpal  bones  of  the  first 
8— A. 


114         ARTICULATIONS   OF   THE   UPPER   EXTREMITY. 

row.  The  anterior  ligament  is  a  broad  membranous  band  connecting 
the  anterior  surfaces  of  the  bones  forming  the  articulation.  The  poste- 
rior ligament  is  less  strong  than  the  anterior,  and  passes  from  the  radius 
to  the  dorsum  of  the  first  three  carpals. 

Mention  the  ligaments  of  the  carpus. 

There  are  three  sets :  1,  articulations  of  first  row  have  two  dorsal^  two 
palmar^  and  two  interosseous  ligaments ;  2,  articulations  of  the  second 
row  have  three  dorsal^  three  palmar^  and  three  iriterosseous  ligaments ; 
3,  articulations  of  the  two  rows  with  each  other  have  anterior^  posterior^ 
external  lateral^  and  internal  lateral  ligaments. 

What  are  the  ligaments  connecting  the  carpus  with  the  meta- 
carpus ? 

The  first  metacarpal  bone  and  the  trapezium  have  a  capsule  and 
separate  synovial  membranes.  The  joints  between  the. carpus  and  four 
inner  metacarpals  have  dorsal,  plantar,  and  interosseous  ligaments. 

The  synovial  membranes  of  all  the  joints  in  the  carpus  and  wrist  proper 
SLveJive  in  number. 

What  are  the  remaining  ligaments  of  the  metacarpus  and 
phalanges? 

Of  the  metacarpals  with  each  other,  there  are  the  dorsal,  palmar,  and 
interosseous  ligaments :  their  digital  extremities  are  connected  by  a  nar- 
row band,  the  transverse  ligament,  presenting  four  grooves  for  tendons. 

The  metacarpo-phalangeal  articulations  have  anterior  and  two  lateral 
ligaments.  The  interphalangeal  articulations  also  have  anterior  and  two 
lateral  ligaments. 

Henle*s  Description  of  the  Wrist-  or  Hand-joint. 

This  includes  tlie  lower  radio-ulnar  articulation,  the  articulation  of  the 
forearm  with  the  carpus,  the  intercarpal  and  carpo-metacarpal  articulations. 
Their  movements  are  all  mutually  compensatory,  and  many  ligaments  are 
common.  To  the  humerus  is  attached  the  ulna,  to  the  ulna  the  radius,  and 
to  the  radius  the  hand. 

1.  The  lower  radio-ulnar  is  a  rotation  joint.  The  curve  of  the  ulnar  articu- 
lar surface  and  that  of  the  sigmoid  cavity  are  not  concentric  arcs,  the  former 
being  a  half-circle  of  |  inch  (16  mm.)  radius,  and  the  latter  an  arc  of  45°  of 
1  inch  (26  mm.)  radius.  The  ligaments  are  capsular  and  inter  articular :  the 
latter  is  not  interarticular  in  the  usual  sense,  but  is  an  extension  inward  of 
the  lower  end  of  the  radius.  At  its  base  it  is  attached  to  a  prominent  edge  of 
the  radius  below  the  sigmoid  cavity  ;  at  its  apex  it  is  attached  by  two  bands, 
an  upper  to  a  little  cavity  at  the  base  of  the  styloid,  and  a  lower  to  the  outer 
surface  of  that  process :  vessels  pass  between  the  two  bands.  Its  upper  sur- 
face articulates  with  the  head  of  the  ulna ;  its  lower  is  concave  and  forms 
part  of  the  carpal  joint.  It  is  perforated  in  the  centre  in  40  per  cent,  of  cases, 
and  is  ^  inch  (5  mm.)  thick  at  its  apex. 

The  capsule  is  strong,  and  continuous  below  with  that  of  the  radio-carpal 
joint :  anteriorly  some  fibres  of  the  pronator  quadratus  are  attached,  by  which 


THE   WEIST   AND   CARPUS.  115 

it  is  pulled  forward  in  pronation ;  posteriorly  it  is  strengthened  by  oblique 
and  transverse  fibres,  and  is  covered  on  the  ulnar  side  by  the  common  carpal 
ligament  (annular).  It  passes  between  the  bones  of  the  forearm  about  ^  inch 
(5  mm.)  above  the  cartilaginous  surfaces,  ending  in  a  blind  sac.  The  synovial 
processes  vary  in  number  and  form :  thin  threads  or  tabs  or  strong  folds  rise 
from  the  posterior  and  inner  capsular  wall. 

2.  Radio-carpal  Joint. — A  line  passing  between  the  radius  and  ulna  divides 
the  lunar  bone,  so  that  the  scaphoid  and  outer  half  of  the  lunar  articulate 
with  the  radius ;  the  inner  half  of  the  lunar  and  the  pyramidal  articulate 
with  the  triangular  fibro-cartilage.  The  carpal  bones  of  this  joint  are  con- 
nected by  strong  interosseous  ligaments  flush  with  the  upper  articular  sur- 
faces. The  extent  of  articular  surface  on  the  carpus  is  greater  than  that  on 
the  forearm,  but  the  convexity  is  smaller  than  the  concavity,  so  that  contact 
is  mesial,  with  room  for  lateral  synovial  pouches.  The  frontal  arc  of  the 
joint-surface  of  the  radius  is  69°  of  If  inches  (42  mm.)  diameter ;  the  sagittal 
arc  is  64°  of  f  inch  (18  to  22  mm.)  diameter. 

The  capsule  is  pretty  firmly  stretched  from  the  edges  of  the  upper  to  the 
edges  of  the  lower  joint-surfaces:  it  is  shortest  and  least  yielding  between 
the  radius  and  lunar,  serving  as  an  axis  of  rotation.  The  strengthening 
fibres  of  the  capsule  are  continuous  with  those  of  the  joint  above.  Synovial 
folds  are  in  the  posterior  and  ulnar  corners  of  the  joint-cavity :  synovial 
bands  with  concave  edges  (ligg.  mucosa),  in  connection  with  the  interosseous 
ligaments  of  the  first  row,  spring  from  the  anterior  and  posterior  J)arts  of  the 
capsule.  This  joint  may  communicate  with  that  of  the  pisiform  or  with  the 
carpal  joint  by  the  lack  of  an  interosseous  ligament. 

3.  Carpal  Joint. — This  is  between  the  bones  of  the  lower  row  and  those  of 
the  upper,  excepting  the  pisiform.  The  trapezoid  and  trapezium  are  con- 
nected at  their  lower  edges  by  a  thin  interosseous  ligament :  there  is  none 
between  the  trapezoid  and  os  magnum,  where  the  carpal  as  a  rule  commu- 
nicates with  the  carpo-metacar pal  joint;  the  cleft  between  the  os  magnum 
and  unciform  is  closed  by  a  large  mass  of  connective  tissue  prolonged  as  a  thin 
membrane  between  their  articular  surfaces.  The  articular  cartilages  of  all  the 
carpal  bones  are  hyaline,  and  ^  inch  (i  to  1  mm.)  thick.  The  head  of  the  os  mag- 
num projects  into  the  cavity  of  the  scaphoid  and  lunar,  allowing  flexion,  ex- 
tension, and  rotation  and  lateral  immobility:  the  axis  of  rotation  is  through 
the  length  of  the  os  magnum,  that  of  flexion  and  extension  across  its  head. 

The  capsule  of  this  joint  includes  the  edges  of  the  cartilaginous  surfaces. 
It  shows  transverse  folds  anteriorly  in  flexion  and  posteriorly  in  extension. 
Synovial  folds  fill  the  corners  and  clefts  between  tlie  bones. 

4.  The  pisiform  joint  has  a  weak  capsule,  attached  at  some  distance  from  the 
articular  surfaces  of  either  bone  (4  mm.  distant  from  that  of  the  pisiform). 

5.  The  General  Carpo-metacarpal  Joint. — This  is  made  up  of  very  irregular 
joint-surfaces  covered  by  hyaline  cartilage  i  to  i  mm.  thick. 

The  capsule  is  strong,  and  fastened  immediately  to  the  edge  of  the  carti- 
laginous surfaces  by  which  the  bases  of  the  metacarpals  articulate  with  each 
other  and  with  the  carpus.  The  pouch  between  the  bases  of  the  third  and 
fourth  metacarpals  is  divided  by  an  interosseous  ligament  into  two  parts,  an. 
anterior  and  posterior.  In  this  same  region  a  sagittal  synovial  fold  passes  up 
between  the  os  magnum  and  unciform,  and  may  completely  divide  the  carpo- 
metacarpal joint. 

6.  The  thumb-carpal  joint  is  elliptical,  saddle-shaped,  so  that  the  convexity 
of  each  surface  seems  to  be  received  into  the  cavity  of  the  other :  it  makes 
an  angle  of  45°  with  the  horizontal,  the  external  edge  being  the  highest. 

The  capsule  is  attached  close  to  the  joint  surface  of  the  trapezium,  but  about 


116  ARTICULATIONS   OF  THE   UPPER   EXTREMITY. 

^  inch  (5  mm.)  away  from  that  of  the  first  metacarpal.  A  synovial  fold  2  mm. 
broad  extends  around  the  joint-cavity,  weakest  on  the  radial  side. 

The  nerves  of  the  above  joints  are  from  the  ulnar,  median,  and  posterior 
interosseous. 

Arteries  of  the  radio-carpal  joint  are  from  the  anterior  and  posterior  carpal 
arches,  the  radial  and  ulnar ;  for  carpal  and  carpo-metacarpal  are  anterior  and 
posterior  carpal  arches,  anterior  and  posterior  interosseous,  and  deep  palmar 
arch. 

Actions. — In  the  radio-carpal  joint  there  is  flexion  associated  with  adduction, 
extension  associated  "with  abduction :  adduction  is  possible  to  45°,  as  the  ulna 
does  not  descend  so  low  as  the  radius ;  abduction  is  slight ;  flexion  is  less  than 
extension.  When  the  hand  is  flexed,  it  cannot  be  ad-  or  abducted,  as  the 
lateral  parts  of  the  capsule  are  taut.  There  is  no  rotation  provided,  as  the 
pronation  and  supination  of  the  radius  answer  that  purpose. 

In  the  carpal  joint  flexion  is  freer  than  extension ;  rotation  is  present,  but 
no  lateral  motion. 

In  the  carpo-metacarjml  joint  there  is  some  flexion  and  extension  on  a  trans- 
verse axis,  possibly  a  little  rotation  on  a  long  axis.  Movements  are  freest  at 
the  margins  of  the  metacarpus  and  least  in  the  centre ;  the  excursion  of  the 
metacarpal  of  the  middle  finger  does  not  exceed  6°. 

The  synovial  cavities  are  five  in  number:  (1)  between  radius  and  ulna,  ulna 
and  fibro-cartilage ;  (2)  in  radio-carpal  joint;  (3)  in  carpal  joint  and  carpo- 
metacarpal; (4)  in  thumb-carpal  joint;  (5)  in  pisiform  joint. 

ACCESSORY  LIGAMENTS   OP  THE  WRIST. 

{a)  What  is  generally  known  as  the  annular  ligament  is  partly  fascial  and 
partly  ligamentous.  The  fascial  portion  is  only  transverse  bands  of  the  fascia 
of  the  forearm,  and  is  called  the  lig.  carpi  commune.  There  is  no  natural, 
but  a  practical,  division  into  anterior  and  posterior  parts  (radial  and  ulnar). 
The  highest  bundles  of  the  ulnar  portion  begin  in  the  middle  of  the  posterior 
surface  of  the  forearm  1  inch  above  the  radio-carpal  joint,  and  run  obliquely 
inward  and  down  to  the  ulnar  margin  of  the  wrist,  and  are  inserted  into  the 
extensor  carpi  ulnaris  tendon.  The  next  lower  set  of  fibres  rise  from  the 
prominent  ridge  on  the  radius,  bounding  externally  the  groove  for  the  ex- 
tensor sec.  inter,  poll.,  and  pass  around  internally  to  the  summit  of  the  pisi- 
form. Farther  down  follow  fibres  from  the  styloid  process  of  the  radius  to 
the  pisiform  and  ulnar  edge  of  the  fifth  metacarpal.  The  fibres  passing  to  the 
pisiform  stop  there ;  those  above  and  below  this  are  continued  externally,  so 
that  a  cleft  is  left  through  which  the  ulnar  nerve  and  vessels  pass  from  be- 
neath the  deep  fascia. 

The  radial  portion  of  the  common  carpal  ligament  passes  from  the  ridge  on 
the  radius  adjacent  to  the  extensor  secundi  poll,  tendon,  over  the  other  two 
extensors  of  the  thumb,  becomes  continuous  with  the  fascia  over  the  ball  of  the 
thumb,  passes  over  the  radial  vessels  and  tendon  of  the  flexor  carpi  rad.,  and  here 
unites  in  part  with  the  tendinous  layer  of  the  "  proper  volar  lig.  of  the  carpus ;" 
it  passes  on  ulnarward,  and  divides  into  a  superficial  and  deep  layer,  the  former 
going  to  the  summit  of  the  pisiform,  covering  the  ulnar  nerve  and  vessels,  the 
latter  passing  beneath  them  to  join  the  ligamentous  portion  of  the  annular 
ligament — i.  e.  the  lig.  c.  volare  proprium.  In  front  of  the  flexor  tendons 
are  therefore  two  ligaments,  grown  together,  only  separable  by  the  knife  in 
the  region  of  the  palmaris  longus ;  the  superficial  one  is  fascia,  lig.  c.  commune, 
the  deep  one  is  ligamentous,  the  lig.  c.  vol.  proprium,  and  both  together  form 
the  anterior  annular  ligament  of  Gray. 

(6)  Accessory  Bands  of  the  Dorsal  Surface.— Onthe  back  of  the  wrist,  between 


ACCESSORY   LIGAMENTS   OF   THE  WEIST. 


117 


the  lig.  c.  comm.  (posterior  annular  lig.)  and  the  joints,  is  a  layer  of  fatty  con- 
nective tissue  containing  vascular  network,  cushioning  the  grooves  and  form- 
ing partition  walls  between  some  of  the  extensor  tendons :  some  of  it  passes 


Fig.  10. 


Dorsal  Surface  of  Wrist. 

down  into  strengthening  bands  of  the  capsules.  1.  Deep  dorsal  ligament  of  the 
carpus  (lig.  carpi  dorsale  profundum),  Fig.  10.  This  consists  of  (1)  nearly 
straight  fibres  from  the  ulna  to  the  pyramidal  (py)  ;  (2)  three  bundles  of  con- 
verging and  arched  fibres  to  the  pyramidal  from  the  lower  margin  of  the  ra- 
dius, its  styloid  process,  and  the  scaphoid  ;  (3)  straight  fibres  from  the  styloid 
of  the  radius  to  the  scaphoid  (s) ;  thence  to  the  trapezium  and  trapezoid ;  (4) 
from  the  lowest  arched  band  slips  go  to  the  os  magnum  and  unciform  ;  (5)  a 
broad  band  (*)  from  the  pyramidal  to  the  unciform,  thence  to  the  base  of  the 
fifth  metacarpal ;  (6)  sometimes  a  narrow  band  (**)  from  the  radius  to  the  os 
magnum. 

2.  Short  Dorsal  Ligaments  of  the  Carpus  (ligg.  carpi  dorsalia  brevia). — These 
include  all  which  connect  adjacent  bones — viz.  ligg.  intercarpea,  carpo-meta- 
carpea,  and  intermetacarpea.  The  dorsal  intercarpals  are  flat,  transverse,  or 
oblique,  and  only  in  the  lower  row ;  those  seen  in  the  upper  row  are  posterior 
edges  of  interosseous  ligaments.  The  dorsal  carpo-metacarpals  pass  obliquely 
between  the  parts  indicated  (Fig.  10) ;  as  a  rule  each  metacarpal  is  united  to 
two  carpals,  only  one  for  the  first.  These  ligaments  on  the  second,  third,  and 
fifth  metacarpals  are  united  with  the  radial  and  ulnar  extensors.  The  dorsal 
intermetacarpals  are  transverse  bands  (Fig.  10)  between  the  metacarpal  bases, 
four  in  number  ;  the  one  between  the  thumb  and  index  is  of  varying  strength. 

(c)  Accessory  Bands  of  the  Anterior  Surface. — 1.  The  proper  volar  ligament  of 
the  carpus  (lig.  carpi  volare  proprium).  This  forms  a  bridge  over  the  ante- 
rior hollow  of  the  carpus,  and  a  great  support  to  the  upper  part  of  the  hand  ; 
it  may  be  called  the  ligamentous  portion  of  the  annular  ligament.  On  the 
ulnar  side  it  rises  from  the  radial  edge  of  the  pisiform,  from  the  hook  of 
the  unciform,  and  from  the  piso-unciform  ligament,  and  sometimes  from  the 


118        ARTICULATIONS   OF   THE  UPPER   EXTREMITY. 

bases  of  the  fourth  and  fifth  metacarpals ;  radially  it  rises  from  the  styloid 
process  of  the  radius,  the  radio-carpal  joint  capsule,  the  tuberosity  of  the 
scaphoid  and  trapezium,  and  base  of  the  first  metacarpal.  Besides  these  at- 
tachments, it  is  connected  with  the  deep  volar  lig.  on  either  side,  the  two 
together  forming  the  canal  for  the  passage  of  the  flexor  tendons.  The  middle 
third  of  the  ligament  is  connected  with  the  lig.  c.  comm.  and  palmaris  long, 
tendon  ;  below  it  is  continuous  with  the  deep  layer  of  the  palmar  fascia. 

2.  The  deep  volar  ligament  of  the  carpus  (lig.  carpi  volare  profundum,  Vpr, 
Fig.  11).  There  is  a  fascia  continuous  with  that  covering  the  pronator  quad- 
ratus  passing  over  the  hand-joints  to  the  anterior  surface  of  the  palmar  inter- 
ossei :  if  this  be  removed,  there  is  left  a  shining,  strong,  ligamentous  mass 
divisible  into  three  parts-i-the  arcuate  above,  the  radiate  in  the  middle,  and 
the  transverse  below  (lig.  carpi  v.  profundum  arcuatum,  radiatum,  and  trans- 
versum). 

(1)  The  upper  fibres  of  the  arcuate  (Vpa)  pass  transversely  on  the  capsule 
from  the  lower  end  of  the  radius  to  the  triangular  fibro-cartilage ;  (2)  the 
next  set  pass  in  an  arched  manner  from  the  styloid  of  the  radius  to  the  pyra- 

FiG.  11. 


Palmar  Surface  of  Wrist. 

midal ;  they  there  unite  with  (3)  straight  fibres  from  the  base  of  the  styloid 
process  of  the  ulna  to  the  os  magnum ;  (4)  fibres  also  pass  from  the  styloid  of 
the  radius  and  from  the  cuneiform  to  converge  upon  the  os  magnum. 

The  middle  portion  of  this  deep  ligament  (Vpr)  sends  its  fibres  radially  from 
the  OS  magnum  in  three  directions,  internally,  externally,  and  downward. 
Those  going  straight  down  descend  to  the  third  metacarpal ;  others,  approach- 
ing a  transverse  direction,  go  to  the  second  metacarpal  on  one  side  and  the 
fourth  and  fifth  on  the  other.  The  internal  fibres  go  to  the  unciform  and  its 
process,  and  upward  to  the  pisiform  joint,  and  there  turn  forward  to  form 
the  proper  volar  ligament  (ligamentous  part  of  the  annular).    The  external 


ACCESSORY   LIGAMENTS   OF  THE   WRIST.  119 

fibres  go  to  the  ulnar  side  of  the  flexor  carpi  radialis  tendon,  to  the  trapezoid 
and  tuberosity  of  the  scaphoid. 

The  transverse  portion  (Vpt)  connects  the  bones  of  the  lower  row  together, 
the  bases  of  the  metacarpals  together,  and  these  two  sets  of  bones  with  each 
other.  The  bundles  form  a  triangular  mass  with  its  apex  down  and  attached 
to  the  third  metacarpal ;  the  base  is  formed  of  transverse  bands  covered  by 
the  radiate  ligament  which  pass  from  bone  to  bone  between  the  trapezium 
and  unciform,  between  the  second  and  fifth  metacarpals.  The  fibres  from  the 
third  metacarpal  go  externally  in  two  layers,  a  superficial  one  in  front  of  the 
tendon  of  the  flexor  c.  radialis  (ki.  Fig.  11),  and  into  the  lig.  c.  vol.  proprium ; 
a  deep  one  behind  this  tendon  to  the  second  metacarpal  and  trapezium  ;  of  the 
internal  fibres,  the  deepest  go  to  the  fourth  and  fifth  metacarpals,  and  the  su- 
perficial to  the  unciform  and  piso-metacarpal  ligament. 

The  height  of  the  lig.  c.  vol.  proprium  is  about  1  inch  (28  mm.) — i.  e.  this  is 
the  length  of  the  canal  enclosing  the  flexor  tendons  and  median  nerve.  The 
lower  opening  of  the  canal  is  f  inch  (21  mm.)  iji  a  transverse  direction,  § 
inch  (11  mm.)  in  a  sagittal  direction.  Diverging  from  the  sides  of  this  opening 
are  the  muscles  of  the  little  finger  and  those  of  the  ball  of  the  thumb. 

A  carpo-metacarpal  band.  Cm,  passes  from  the  tuberosity  and  ridge  of  the 
trapezium  to  the  base  of  the  first  metacarpal. 

{d)  Accessory  Ligaments  of  the  Ulnar  Side. — (1)  Piso-hamatum  (Ph,  Fig.  11)< 
from  the  apex  of  the  pisiform  to  the  hook  of  the  unciform,  united  at  its  upper 
edge  with  the  lig.  c.  vol.  proprium;  (2)  lig.  piso-metacarpeum  (Pm),  really  a 
continuation  of  the  flexor  carpi  uln.  tendon,  passes  fan-shaped  from  the 
pisiform  to  the  anterior  surface  of  the  base  of  the  fifth,  fourth,  and  third 
metacarpals ;  (3)  lig.  hamo-metacarpeum,  Hm,  passes  from  the  ulnar  surface 
of  the  hook  of  the  unciform  to  the  fifth  metacarpal. 

(e)  Accessory  Ligaments  of  the  Interspaces  of  the  Metacarpals. — Ligg.  inter- 
metacarpea  interossea,  connecting  the  bases  of  the  metacarpals,  strengthening 
the  Capsules  below,  and  running  from  the  posterior  edge  of  the  external  bone 
to  the  anterior  edge  of  the  internal  one. 

Metacarpo-phalangeal  Articulations. — The  head  of  a  metacarpal  bone  with  its 
hyaline  cartilage  forms  a  half-sphere  of  |  inch  (9  mm.)  radius,  with  a  segment 
cut  ofi"  from  each  side.  The  concavity  of  the  articulating  phalanx  is  quite  flat, 
and  belongs  to  a  curve  of  greater  radius  than  the  head  it  receives,  {a)  The 
capsule  is  very  thin,  but  strengthened  on  all  sides  by  ligaments  or  tendons,  and 
is  lined  by  synovial  tissue.  In  the  thumb,  sometimes  index  and  little  finger, 
are  to  be  found  in  the  anterior  wall  of  the  capsule  sesamoid  bones :  their  sur- 
faces, which  lie  in  the  joint-cavity,  are  covered  with  hyaline  cartilage,  and  a 
synovial  fold  runs  between  them. 

{h)  Accessory  Bands.— Two  lateral  ligaments,  lig.  accessorium  (radiale  and 
ulnare) :  these  are  rounded  cords  running  on  either  side  from  the  tubercle  on 
the  side  of  the  head  of  the  metacarpal  and  a  little  fossa  in  front  of  this  to  the 
base  of  the  first  phalanx. 

The  anterior  ligaments  (ligg.  capitulorum  volaria)  are  made  of  transverse 
bands  coming  from  several  directions :  the  connective  tissue  covering  the  in- 
terossei  presents  near  the  heads  of  the  metacarpals  strong  transverse  fibres 
which  pass  over  the  capsule  and  between  the  capsules  of  the  four  inner  meta- 
carpo-phalangeal joints.  A  part  passes  forward  on  either  side,  and  forms  a 
smooth  tube  for  the  fiexor  tendons  over  the  joints,  and  for  the  lumbrical 
muscles  over  the  ligg.  capitulorum  ant.  The  anterior  walls  of  the  tubes  for 
the  flexor  tendons  are  the  ligg.  vaginalia,  transverse  bands  fastened  to  the 
edges  of  the  phalanx.  These  are  also  {ligg.  dorsalia)  connected  with  the  ante- 
rior and  side  walls  of  the  capsule,  which  pass  back  over  the  lateral  ligaments 


120  ARTICULATIONS   OF   THE   LOWER   EXTREMITY. 

through  some  tendinous  fibres  of  the  interossei  to  the  extensor  tendons,  which 
are  enclosed  by  them,  and  thus  held  down  for  the  protection  of  the  back  of 
the  joint.  Lower  transverse  dorsal  bands  (ligg.  capitulorum  dorsalia)  are 
stretched  from  finger  to  finger  between  the  ligg.  dorsalia. 

Sometimes  there  are  bursse  between  the  adjacent  joint-capsules  at  the  lower 
ends  of  the  metacarpals. 

The  movements  of  these  joints  are  flexion,  extension,  ad-  and  abduction,  cir- 
cumduction, and  rotation.  When  the  finger  is  flexed,  the  lateral  ligaments 
are  tense  and  prevent  ad-  and  abduction  of  fingers  and  rotation  of  the  first 
phalanx  on  a  long  axis. 

Articulations  of  the  Phalanges. —  Capsular  and  accessory — two  lateral,  ligg.  vagi- 
nalia,  ligg.  dorsalia,  and  retinacula  tendinum  (folds  of  synovial  membrane).  Ana- 
logues of  the  ligg.  capitulorum  (transverse  ligament,  Gray)  remain  as  fibrous 
septa  passing  laterally  from  the  capsules  to  the  skin  of  the  fingers. 

Movements  are  flexion  and  extension. 

ARTICULATIONS  OF  THE  LOWER  EXTREMITY. 

THE  PELVIC  GIRDLE. 
Describe  the  special  ligament  of  the  hip-bone. 

This  is  the  obturator  ligament,  or  membrane  partly  closing  in  the  ob- 
turator foramen,  presenting  small  holes  here  and  there,  in  some  places 
layers  and  a  general  horizontal  direction.  As  it  passes  from  one  obtura- 
tor tubercle  to  the  other  it  forms  the  obturator  canal,  passing  down  and 
forward,  filled  with  fat,  the  obturator  vessels,  and  nerve.  Above  and 
anteriorly  the  ligament  is  attached  to  the  margin  of  the  foramen  on  a 
plane  with  the  anterior  (really  inferior)  surface  of  the  os  pubis ;  below 
and  behind  it  is  attached  so  as  to  be  flush  with  the  pelvic  surface  of  the 
OS  pubis.  From  its  inner  margin  rise  fibres  of  the  obturator  internus 
muscle,  and  from  the  lower  part  of  the  outer  margin  fibres  of  the  obt. 
externus.  The  upper  part  of  the  outer  surface  is  filled  by  fat,  which  is 
covered  by  single  flat  bands  going  from  the  ligament  to  the  external  edge 
of  the  foramen  and  to  the  capsule  of  the  hip-joint. 

The  lig.  iliacum  proprium  is  sometimes  stretched  across  the  concavity  of  the 
ilio-pectineal  line. 

Describe  the  ligaments  between  the  two  hip-bones. 

The  only  articulation  is  the  symphysis  pubis,  which  shows  many  vari- 
eties. The  bone-surfaces  are  covered  by  layers  of  hyaline  cartilage  con- 
nected to  the  bone  by  nipple-like  processes :  these  plates  often  contain 
bony  kernels.  The  space  between  the  cartilages  is  filled  in  part  with 
fibro-cartilage  and  in  part  with  clear  fibrous  substance ;  the  size  of  the 
space  is  greater  in  front  and  below  where  the  edges  diverge :  in  the  pos- 
terior half  of  the  synchondrosis  the  cartilages  are  parallel,  and  lie  so  close 
that  the  interposed  substance  looks  like  a  fine  white  line.  In  the  upper 
and  back  part  of  the  interposed  substance  is  a  median  split  with  smooth 
walls  lined  by  elastic  fibro-cartilage :  up  to  the  seventh  year  this  cleft  is 
occupied  by  fibrous  substance  containing  little  holes,  which  later  unite 
into  a  larger  cleft  and  may  contain  synovia.     Whether  this  is  more  com- 


LIGAMENTS  BETWEEN  BONES  OF  TRUNK  AND  HIP-BONE.    121 

mon  in  pregnancy  is  not  settled :  the  cleft  is  not  so  often  lacking  in  wo- 
men as  in  men. 

For  ligaments  Gray  describes  anterior^  postefinor,  superior^  and  subpu- 
bic, and  an  interposed  ^6ro-car^i7a^e. 

Henle  finds  that  the  cartilages  are  mainly  continuous  with  the  perios- 
teum and  muscle-tendons  of  the  region.  The  upper  edge  and  posterior 
surface  of  the  joint  are  covered  only  by  periosteum,  -^^  i^ch  (J  mm. )  thick, 
consisting  of  transverse  fibres.  In  front  is  a  thick  layer  of  connective 
tissue  continuous  with  the  periosteum,  and  the  attachment  of  abdominal 
muscles  and  adductors  of  the  thigh.  In  common  with  this  is  the  lig.  arcu- 
atum  pubis  (posterior  layer  of  triangular  ligament),  which  is  stretched 
between  the  rami  of  the  pubis  as  a  diaphragm  to  a  puint  f  inch  (9  mm. ) 
below  the  bony  subpubic  arch :  only  the  middle  part  of  the  lower  edge 
is  free,  limiting  the  hole  through  which  passes  the  dorsal  vein  of  the 
penis ;  laterally  it  is  continuous  with  the  obturator  internus  fasciae. 


LIGAMENTS  BETWEEN  THE  BONES    OP  THE  TRUNK 
AND  HIP-BONE. 

Describe  the  ligaments  of  the  ilio-sacral  joint. 

^   Capsule,  accessory  2LTe — ilio-lumbar,  anterior,  interosseous,  SLud posterior 
ilio-sacral,  great  saa^o-sciatic,  small  sacro-sdatic. 

The  ilio-sacral  joint  (sacro-iliac)  is  between  the  auricular  surface  on  the 
ilium  and  a  corresponding  one  on  the  first  three  vertebrae  of  the  sacrum : 
the  cartilage  is  hyaline,  2  to  3  mm.  thick  on  the  sacrum  and  1  mm.  thick 
on  the  ilium.  The  sacrum  is  held  in  position  mostly  by  ligament  and 
partly  by  a  sort  of  mortise  between  the  bones  (Fig.  12). 


Fig.  12. 


rANA»- 


CAN 


The  capsule  is  firmly  stretched  over 
the  joint-cavity,  strengthened  exter- 
nally by  horizontal  fibres,  within  by  soft 
vascular  connective  tissue  covered  by 
periosteum.  ^  On  the  pelvic  ^  surface 
the  capsule  is  not  attached  immedi- 
ately to  the  edges  of  the  bones,  but 
farther  away,  leaving  a  little  space 
for  synovia:  small  synovial  tufts  are 
found  in  this  space  and  between 
the  upper  edges  of  the  cartilaginous 
surfaces. 

Accessoi^  Bands. — (1)  llio-lumbar 
Ligament.^ — The  posterior  layer  of  the 
sheath  of  the  quadratus  lumborum 
muscle  is  the  lumbo-costal  hgament, 
being  a  union  of  representatives  of  the 
costo- transverse  and  intercostal  liga- 
ments of  this  region.  The  anterior 
layer  of  this  sheath  is  thin  above,  and  may  be  a  part  of  the  lumbo-costal 


Section  through  the  Second  Sacral  Ver- 
tebra parallel  to  the  Pelvic  Inlet. 


122  AETICULATIONS   OP   THE   LOWER   EXTREMITY. 

ligament,  but  below  it  is  called  the  ilio-lumbar.  It  rises  in  part  from  the 
anterior  surface  of  the  fourth  lumbar,  some  fibres  descending  to  the  fifth 
transverse  process :  a  strong  falciform  band  envelops  at  its  origin  the  trans- 
verse process  of  the  fifth  and  passes  out  upon  the  crest  of  the  ilium ;  a  part 
from  the  base  of  the  fifth  process  descends  into  the  pelvis,  covers  the  upper 
part  of  the  ilio-sacral  joint,  and  is  lost  on  the  periosteum.  These  descend- 
ing bands  (lumbo- sacral  of  Gray)  represent  anterior  costo-transverse  liga- 
ments, and  form  external  boundaries  to  the  openings  through  which  pass 
the  anterior  branches  of  the  fourth  and  fifth  lumbar  nerves.  Inter- 
nal to  these  run  flat  bands  vertically  from  the  root  of  a  transverse  pro- 
cess and  intervertebral  cartilage  to  corresponding  points  next  below: 
they  serve  as  bridges  over  vessels  and  as  heads  of  origin  for  the  psoas 
muscle. 

(2)  Ilio-sacral  Ligaments. — The  capsule  of  this  joint  is  strengthened 
anteriorly  by  thin  bands,  the  anterior  ilio-sacral  ligament.  Posteriorly 
connecting  the  tuberosities  of  the  two  bones  is  a  great  number  of  flat  and 
cylindrical  bands  separated  by  masses  of  fat:  the  whole  mass  is  the  in- 
terosseous  ilio-sacral  ligament.  Two  bands  rise  from  the  first  and  second 
articular  processes  of  the  sacrum,  and  a  third  very  oblique  one  from  the 
third  process,  and  pass  up  to  the  posterior  superior  spine  of  the  ilium : 
these  are  the  posterior  ilio-sacral  ligaments.  (3)  The  great  sacro-sciatic 
ligament  (posterior),  or  lig.  sacro-tuberosum,  is  formed  of  several  layers 
enclosing  fat  and  muscle.  It  rises  by  a  broad  base  from  the  posterior 
inferior  spine  and  from  a  little  of  the  adjoining  iliac  crest,  from  the 
fourth  and  fifth  articular  processes  of  the  sacrum,  the  free  lateral  margin 
of  that  bone,  and  of  the  two  upper  coccygeal  vertebrae.  It  passes  down, 
out,  and  forward,  becomes  narrow  and  thick  in  the  middle,  and  is  in- 
serted into  the  inner  margin  of  the  tuber  ischii ;  thence  it  is  prolonged 
forward  as  the  falciform  ligament^  forming  a  groove  with  the  bone  for 
the  internal  pudic  vessels  and  nerve.  Some  fibres  of  this  ligament 
pass  to  the  tendon  of  the  biceps  and  semitendinosus :  others  from  the 
posterior  superior  spine  of  the  ilium  pass  straight  down  to  the  rudiment- 
ary transverse  processes  of  the  third,  fourth,  and  fifth  sacral  vertebrae.  ^ 

(4)  The  small  sacro-sciatic  ligament  (anterior),  lig.  sacro-spinosum,  is 
triangular  and  attached  by  its  apex  to  the  posterior  surface  of  the  spine 
of  the  ischium  and  by  its  base  to  the  free  lateral  margin  of  the  sacrum 
and  upper  coccygeal  vertebrae :  it  is  attached  posteriorly  to  the  great 
ligament,  and  forms  the  inferior  boundary  of  the  great  sacro-sciatic  fora- 
men and  upper  boundary  of  the  small  foramen.  It  should  hardly  be 
called  a  ligament,  as  it  is  so  intimately  connected  with  the  coccygeus 
muscle :  ligamentous  and  muscular  fibres  cross  each  other  at  acute  angles, 
and  sometimes  the  ligament  is  almost  wholly  muscular. 

A  superior  sacro-spinous  ligament  has  been  seen,  forming  a  middle  sacro- 
sciatic  foramen. 

The  great  sciatic  notch  is  partly  filled  by  the  pyriformis  muscle ;  above 
this  pass  the  gluteal  vessels  and  superior  gluteal  nerve,  and  below  it  the 


THE   HIP- JOINT.  123 

sciatic  vessels  and  nerve,  internal  pudic  vessels  and  nerve,  and  muscular 
branches  of  the  sacral  plexus. 

The  small  foramen  transmits  the  tendon  of  the  obturator  internus 
muscle,  its  nerve,  the  internal  pudic  vessels  and  nerve. 

THE  HIP-JOINT. 
Describe  the  hip-joint. 

It  is  a  ball-and-socket  joint,  with  arcs  of  f  inch  (22  mm. )  radius : 
the  radius  of  the  circular  edge  of  the  acetabulum  is  about  f^  inch  (2 
mm. )  smaller  than  that  of  the  head  of  the  femur.  The  articular  sur- 
face of  the  head  of  the  femur  is  more  than  a  hemisphere :  any  section 
of  the  bony  acetabulum  through  its  centre  is  less  than  180°. 

The  ligaments  are — cotyloid^  transverse^  teres,  capsular ;  accessory  are — 
orhicular  zone^  ilio-femoral ,  {lio-trocJianteric^puho-femoral^  ischio-femoral, 
and  iscMo-capsular. 

The  cotyloid  consists  of  connective  tissue  arranged  circularly:  it  is 
strengthened  and  fastened  to  the  edge  of  the  acetabulum  by  short  fibres 
rising  at  different  points  and  interlacing  at  acute  angles.  It  is  prismoid 
on  section,  and  embraces  the  head  of  the  femur  so  tightly  that  air  does 
not  enter  the  joint.  Both  its  sides  are  covered  with  synovial  membrane. 
Inferiorly  the  cotyloid  becomes  flat  and  bridges  over  the  acetabular  notch 
as  the  transverse  ligament;  it  turns  one  surface  upward  and  one  down ; 
one  edge  looks  within  and  limits  a  split  through  which,  enveloped  in  fat, 
blood-vessels  enter  the  socket;  the  other  edge  passes  uninterruptedly 
into  the  cotyloid  ligament. 

The  articular  cartilage  of  the  acetabulum  is  2  mm.  thick,  a  little  thinner 
toward  the  centre ;  that  on  the  head  of  the  femur  is  thickest  at  the 
centre,  \  inch  (4  mm.).     The  fossa  acetabuli  contains  a  fat  pad. 

The  ligamentiim  teres  is  misnamed,  being  neither  ligamentous  nor 
round ;  it  is  somewhat^  triangular.  It  is  planted  by  its  apex  into  the 
fossa  on  the  posterior  inferior  quadrant  of  the  head  of  the  femur,  and 
rises  from  the  notch  and  fossa  acetabuli.  Unoccupied  space  around  it 
is  filled  with  synovia.  ^  A  cross-section  of  it  discloses  an  outer  firm  and 
an  inner  loose  part :  it  is  made  up  of  transverse  fibres  limited  by  the 
transverse  ligament  and  longitudinal  fibres,  which  rise  from  the  acetabular 
fossa,  and  some  pass  in  from  the  capsule  under  the  transverse  ligament. 
Its  function  may  be  (1)  to  check  movement;  (2)  a  remnant  from  lower 
animals ;  (3)  to  carry  synovia  and  vessels  (this  is  most  probable).  The 
motion  it  checks  is  a  most  unnatural  one — viz.  is  tense  with  thigh  flexed, 
adducted,  and  rotated  in.  Sometimes  it  is  a  mere  synovial  fold,  and 
sometimes  is  wanting. 

The  capsule  springs  from  the  outer  surface  of  the  base  of  the  cotyloid, 
from  the  edge  of  the  acetabulum  and  margin  of  the  transverse  ligament; 
below  it  is  attached  to  the  anterior  intertrochanteric  line  and  to  the  back 
of  the  neck  of  the  femur  in  a  line  parallel  to  the  posterior  intertrochanteric 
and  about  J  inch  above  it.   The  digital  fossa  is  outside  the  capsule :  it  is  im- 


124  ARTICULATIONS   OF   THE   LOWER   EXTREMITY. 

possible  to  have  a  true  extracapsular  fracture  of  the  neck  of  the  femur. 
At  the  attachment  to  bone  the  innermost  layer  of  the  capsule  is  reflected 
in  smooth  or  longitudinal  folds  (retinacula)  up  the  neck  to  the  articu- 
lar cartilage  of  the  head,  with  which  it  fuses.  This  layer  of  the  cap- 
sule lined  by  epithelium  is  a  thin  but  firm  membrane,  seen  by  the 
microscope  to  be  formed  of  parallel,  transverse,  or  circular  bands; 
outside  this  are  connective-tissue  layers  separating  it  from  the  acces- 
sory bands. 

The  accessory  ligaments  are  either  circular  or  longitudinal.  The  cir- 
cular bands  form  the  zona  orbicularis^  which  is  most  distinct  on  the  under 
wall  of  the  capsule,  because  less  covered  here  by  the  longitudinal  bands. 
It  occupies  the  middle  third  of  the  capsule,  and  continues  upon  the  upper 
and  lower  thirds  as  transverse  or  scattering  bands  of  connective  tissue. 

The  accessory  longitudinal  bands  spring  from  each  of  the  three  bones 
forming  the  acetabulum,  and  are  only  lacking  in  that  part  of  the  capsule 
which  rises  from  the  transverse  ligament.  They  go  between  the  circular 
fibres,  over  them,  or  end  in  them. 

The  ilio-femoral  ligament  extends  obliquely  across  the  front  of  the 
capsule,  attached  above  to  the  lower  part  of  the  anterior  inferior  spine, 
and  from  a  point  behind  this,  just  above  the  acetabulum,  and  below  to 
the  whole  length  of  the  anterior  intertrochanteric  line.  It  is  covered  by 
a  fine  layer  of  circular  fibres,  and  pierced  by  some  fibres  of  origin  of  the 
outer  head  of  the  rectus  femoris.  At  its  insertion  it  is  divided  into  two 
bands — one  to  the  lower  part  of  the  line  and  base  of  the  small  trochan- 
ter, and  one  to  the  upper  part.  Sometimes  it  does  not  divide,  form- 
ing then  a  triangular  band.  It  is  called  the  inverted  ^ -ligament  of 
Bigelow  and  lig.  of  Bertin.  It  is  of  great  importance  in  maintaining 
the  erect  position  of  the  body,  and  requires  250  to  750  pounds  for  its 
rupture. 

The  ilio-trochanteric  ligament  rises  from  beneath  the  anterior  inferior 
spine,  and  may  be  considered  as  the  upper  arm  of  the  Y-ligament  or  as 
fibres  parallel  to  it,  and  inserted  into  the  anterior  part  of  the  base  of  the 
great  trochanter. 

The  puho-femoral  ligament  may  be  described  in  three  parts  at  its 
origin :  the  first  is  a  continuation  of  the  fascia  over  the  pectineus  muscle, 
and  goes  from  the  ilio-pectineal  eminence  down  between  the  ilio-psoas 
and  pectineus  muscles  to  the  lowest  part  of  the  capsule ;  a  second  fascic- 
ulus (pubo-femoral  of  Barkow)  comes  beneath  the  pectineus  from  the 
whole  length  of  the  obturator  crest,  and  joins  the  first  set  outside  that 
muscle ;  a  third  set  comes  from  the  upper  ramus  of  the  pubis  and  upper 
obturator  spine  and  joins  the  others :  it  gives  origin  to  some  fibres  of  the 
obturator  externus. 

The  ischio- capsular  ligament  rises  from  the  lower  part  of  the  edge  of 
the  acetabulum  and  neighboring  portion  of  the  ischium,  and  ends  in  the 
lower  and  outer  portion  of  the  orbicular  zone. 

The  ischio-femoral  ligament  (Macalister)  rises  from  the  upper  part  of 
the  ischial  tuberosity,  passes  over  the  groove  between  this  tuberosity  and 


THE   KNEE-JOINT.  128 

the  acetabulum,  and  is  attached  to  the  back  of  the  neck  at  a  point  mid- 
way between  the  two  trochanters.     It  is  often  fused  with  the  capsule. 

Synovial  processes  occupy  the  joint  outside  the  fatty  pad  of  th^  fossa 
acetabuli  and  in  the  region  of  the  neck  of  the  femur :  broad  flaps  hang 
from  the  capsular  covering  of  the  neck,  or  thin  tufts  give  a  velvety  ap- 
pearance to  the  inner  surface  of  the  capsule. 

The  ilio-psoas  bursa  opens  into  the  joint  anteriorly,  and  is  analogous 
to  the  subscapular  bursa  of  the  shoulder :  it  may  act  as  an  accessory 
pouch  for  synovial  supply  as  needed.  Where  the  capsule  is  thin,  mus- 
cles strengthen  it:  in  front  is  the  ilio-psoas;  above,  the  rectus  and 
gluteus  minimus;  internally,  the  obturator  externus  and  pectineus; 
behind,  the  pyriformis,  two  obturators,  two  gemelli,  and  quadratus 
femoris. 

Nerves  are  from  the  sacral  plexus,  great  sciatic,  nerve  to  quad.  fem. 
muscle,  obturator,  accessory  obturator,  and  anterior  crural. 

The  arteries  are  from  the  obturator,  sciatic,  gluteal,  internal  and  ex~ 
ternal  circumflex. 

Movements  are  in  every  possible  direction.  Flexion  and  extension  pass 
through  139°  on  the  dead  subject,  about  86°  on  the  living ;  ab-  or  adduc- 
tion through  90°,  and  rotation  through  51°.  Flexion  is  checked  by  soft 
parts  and  by  hamstring  muscles  (with  knee  extended),  by  posterior 
part  of  capsule  and  ischio-capsular  ligament ;  extension  is  checked  by  the 
anterior  part  of  the  capsule  and  ilio-femoral  ligament ;  rotation  out^  by 
upper  arm  of  iho-femoral;  rotation  in,  by  ischio-capsular  and  ischio- 
femoral ligaments ;  abduction,  by  pubo-femoral  lig.  and  lower  and  inner 
parts  of  capsule  and  impact  of  head  of  femur ;  adduction,  by  upper 
arm  of  Y-ligament,  by  ilio-trochanteric  lig. ,  and  by  soft  parts. 
^  Ilio-femoral  lig.  checks  extension  and  tendency  to  tip  backward,  rota- 
tion out,  and  adduction.  Piibo-femoral  checks  abduction.  Ischio-femo- 
ral  checks  rotation  in,  extraordinary  flexion. 

THE  KNEE-JOINT. 
Describe  the  knee-joint. 

This  is  a  double  condylar  joint,  really  consisting  of  three  articulations, 
one  between  each  condyle  and  the  tibia,  one  between  the  patella  and 
femur.     The  lig.  mucosum  indicates  the  original  separation  of  the  syno- 
vial sac  into  two. 
The  ligaments  are — 

Accessory. 

External  semilunar  cartilage.  Anterior : 

Internal  semilunar  cartilage.                      Fascia  lata. 

Coronary.  ]ig.  patellae. 

Anterior  crucial.  Lateral  patellar  ligaments. 

Posterior  crucial.  Transverse. 

Capsular.  Posterior : 

Ligg.  alaria.  Popliteal  oblique. 


126  ARTICULATIONS   OF   THE   LOWER   EXTREMITY. 

Lig.  mucosum.  Popliteal  arcuate. 

Retinaculum  or  short  ext.  late- 
ral. 
External : 

External  lateral. 
Internal : 

Long  internal  lateral. 
Short  internal  lateral. 

The  bones  are  covered  with  hyahne  cartilage  to  the  average  depth  of 
J  inch  (4  mm. ).  On  the  anterior  part  of  the  condylar  surface  is  a  trans- 
verse groove  caused  by  the  indentation  of  the  fibro-cartilages :  the  part 
above  this  groove  articulates  with  the  patella.  The  free  posterior  part 
of  the  condyle  corresponds  to  a  radius  of  f  inch  (17  mm.). 

The  joint-surface  of  the  tibia  is  much  flatter  than  that  of  the  femur, 
and  the  disproportion  is  made  up  by  the  internal  and  external  semilunar 
fihro-cartilages  (meniscus  medialis  and  lateralis).  Their  upper  surfaces 
are  concave,  their  outer  edges  J  inch  (6  mm.)  high,  and  lower  surfaces  flat. 
These  ligaments  are  composed  of  horizontally  arched  fibres :  near  their 
outer  edges  they  split  into  two  layers,  between  which  run  nutrient  vessels. 
Their  upper  surfaces  are  covered  with  a  strong  fibro-cartilaginous  mem- 
brane 1  mm.  thick. 

The  external  cartilage  is  nearly  circular,  its  anterior  extremity  being 
inserted  in  front  of  the  spine  of  the  tibia  and  its  posterior  into  both  the 
inner  and  outer  peak  of  the  spine.  The  width  of  this  cartilage  is  about 
f  inch  (13  mm.). 

The  internal  cartilage  forms  nearly  a  half-circle,  and  is  elongated  from 
before  backward.  Its  anterior  extremity  is  in  front  of  the  anterior  cru- 
cial ligament,  its  posterior  extremity  in  front  of  the  posterior  crucial  hg- 
ament.     This  is  widest  behind,  17  mm.,  and  gets  narrower  in  front. 

Coronary  ligaments  connect  the  convex  borders  of  these  cartilages  to 
the  head  of  the  tibia :  they  are  derived  in  part  from  the  lateral  ligaments. 

The  crucial  ligaments  partly  form  a  sagittal  partition  wall  inside  the 
joint,  making  a  right  and  left  chamber  in  its  posterior  half  They  are 
not  like  the  lig.  teres,  but  are  remains  of  original  joints.  Between  them 
is  loose  connective  tissue,  sometimes  little  bursae.  They  are  named  from 
their  tibial  origins.  The  anterior  rises  in  front  of  the  external  meniscus, 
passes,  fan-shaped,  up,  back,  and  out  to  the  posterior  part  of  the  inner 
surface  of  the  external  condyle  :  the  fibres  rising  most  externally  are  in- 
serted most  posteriorly. 

The  posterior  ligament^  a  little  stronger  than  the  anterior,  rises  from 
the  floor  of  the  popliteal  notch  on  the  tibia,  and  passes  up  and  forward 
to  the  anterior  part  of  the  outer  surface  of  the  inner  condjde — i.  e.  to  the 
inner  wall  of  the  intercondylar  fossa  of  the  femur :  this  crosses  behind  the 
anterior  one,  forming  an  X,  and  its  posterior  surface  becomes  external. 

The  crucial  ligaments  receive  fibres  from  the  semilunar  cartilages, 
rarely  any  from  the  inner  to  the  anterior  ligament :  some  pass  from  the 


THE   KNEE-JOINT.  127 

posterior  end  of  the  external  semilunar  to  the  posterior  crucial  (third 
crucial),  either  to  its  posterior  or  its  anterior  surface,  or  they  surround  it. 

The  capsule  of  the  joint  rises  anteriorly  to  a  point  on  the  femur  f  inch 
to  3  inches  (1.5  to  8  cm.)  above  its  articular  surface  ;  thence  it  slopes  to 
the  epicondyles ;  posteriorly  it  is  attached  just  above  the  condyles  and  to 
a  line  between  them  and  to  the  gastrocnemius  and  popliteus.  On  the 
anterior  surface  of  the  femur  it  is  underlaid  with  rich  masses  of  fat :  on 
the  patella  it  is  attached  close  to  the  edges  of  its  posterior  surface,  and 
on  the  tibia  close  beneath  the  articular  cartilages,  and  is  connected  with 
the  origin  of  the  post-crucial  lig. 

Anteriorly,  above  the  patella,  the  capsule  is  united  with  the  extensor 
tendon :  below  this  and  the  patella  it  is  continued  as  a  broad  roll  to  the^ 
tibia,  stretched  in  flexion,  and  in  extension  drawn  forward  by  a  speciar 
muscle.  On  the  sides  the  capsule  is  united  to  the  circumference  of  the 
semilunar  cartilages :  it  presents  two  layers — one  of  vertical  connective- 
tissue  fibres  to  the  edges  of  the  cartilages,  and  an  inner  smooth  vascular 
layer  covering  their  upper  surfaces :  this  also  covers  the  crucial  ligaments, 
so  that  really  the  semilunar  cartilages  and  crucial  ligaments  are  outside 
the  sac  of  the  capsule. 

Synovial  Bur  see  and  Ldgaments. — ^By  the  semilunar  cartilages  is  the 
joint  divided  into  an  upi)er  and  lower  chamber,  and  by  the  crucial  liga- 
ments is  each  chamber  divided  into  lateral  halves :  into  one  or  other  of 
these  cavities  the  subcrural  synovial  pouch  opens.  There  is  a  constant 
communication  with  the  popliteal  hursa^  which  is  between  the  popliteus 
muscle  and  the  posterior  wall  of  the  lower  and  outer  chamber  of  the 
joint.  In  1  out  of  80  cases  there  is  a  communication  with  the  upper 
tibio-fibular  joint. ^  The  groove  for  the  popliteus  is  covered  with  carti- 
lage which  is  continuous  with  that  of  the  upper  tibio-fibular  joint.  The 
openings  from  the  joint  into  the  subcrural  pouch  are  various  in  number 
and  position,  or,  most  rarely,  are  absent. 

The  bursa  semimembranosa  lies  between  the  external  surface  of  the 
semimembranosus  tendon  and  the  inner  head  of  the  gastrocnemius :  it 
is  about  2  inches  (5  cm.)  long,  sometimes  simple  and  sometimes  split  by 
septa.  It  communicates  with  the  knee-joint  in  about  one-half  the  cases, 
more  often  with  the  right  knee,  and  more  often  in  robust  subjects,  and 
never  in  children. 

The  knee-joint  contains  large  fatty  synovial  folds  and  tufts :  the  most 
constant  are  the  ligamenta  alaria  (plica  synov.  patellaris),  which  is  sep- 
arated in  front  from  the  capsule  by  a  mass  of  fat,  and  rises  up  behind 
the  articular  surface  of  the  patella  to  near  its  upper  edge.  By  the  ver- 
tical ridge  on  the  posterior  patellar  surface  it  is  divided  more  or  less  into 
its  two  wings  (alse) :  its  upper  ^digQ  is  concave  and  unites  with  the  lat- 
eral edges  of  the  patella.  In  flexion  of  the  joint  it-  enters  as  a  pad  be- 
tween the  patella  and  tibia.  Its  position  is  secured  by  the  lig.  mucosum 
(lig.  plicae  synov.  patellaris),  which  rises  from  the  bottom  of  the  joint 
and  passes  free  in  a  sagittal  direction  through  it  to  the  anterior  edge  of 
the  intercondyloid  fossa  of  the  femur,  rarely  attached  to  the  spine  of  the 


128  ARTICULATIONS   OF   THE   LOWER   EXTREMITY. 

tibia  or  anterior  crucial  ligament.  At  its  insertion  it  is  usually  flat  and 
broad,  in  the  middle  cylindrical.     It  may  be  no  larger  than  a  thread. 

Synovial  tufts  are  most  numerous  on  the  anterior  wall  of  the  joint 
above  the  patella.  Small  folds  and  strings  and  little  follicles  of  the  cap- 
sule lie  near  its  insertion  into  the  tibia.  Synovia  occupies  the  spaces  not 
filled  by  synovial  folds  or  fat  pads. 

Accessory  bands  are  found  upon  the  anterior,  posterior,  external,  and 
internal  walls. 

L  Anteriorly  the  accessory  bands  form  three  layers:  (1)  The  most 
superficial  is  a  continuation  of  the  fascia  lata,  converging  symmetrically 
on  either  side  to  be  inserted  into  the  tibia  or  lig.  patellae;  some  pass 
horizontally  in  front  of  the  lig.  patellae  and  patella.  (2)  The  middle 
'consists  of  tendons  and  ligaments  around  the  patella.  ^  (3)  The  deepest 
set  is  transverse.  To  the  second  set,  the  centre  of  which  is  the  patella, 
belongs  the  extensor  tendon  of  the  leg  and  three  bands-:  the  lowest  is 
the  Ug.  patellce  (lig.  patellare  inf ),  ^  inch  (4  mm.)  thick,  embracing  the 
apex  of  the  patella,  and  passing  down  and  back  to  the  tubercle  of  the 
tibia  with  undiminished  size.  Between  this  ligament  and  the  capsule  is 
a  mass  of  fat ;  between  it  and  the  head  of  the  tibia  is  the  suhpatellar 
bursa;  between  it  and  the  tubercle  of  the  tibia  is  2ipretibial  bursa.  The 
side  bands  of  the  patella  (lig.  patellare  laterale  and  mediale)  are  thin, 
membranous,  and  triangular.  They  rise  by  their  apices  from  the  epi- 
condyles  of  the  femur,  and  pass  forward  to  the  sides  of  the  patella,  to 
the  posterior  surface  of  the  extensor  tendon  and  lig.  patellae,  often  sepa- 
rated from  the  capsule  by  cellular  bursae.  The  deepest  set  forms  the 
transverse  ligament,  more  or  less  covered  with  fat,  and  passing  from  the 
upper  surface  of  the  internal  semilunar  cartilage  near  its  anterior  ex- 
tremity to  the  anterior  convexity  of  the  outer.  It  is  variable,  may  be 
round  or  flat,  or  lacking,  or  pass  from  one  cartilage  into  synovial  folds. 

2.  The  posterior  capsular  wall  has  a  complicated  structure  due  to  its 
connection  with  various  muscle  tendons.  Above  the  condj^les  the  cap- 
sule is  compact,  but  lower  it  shows  two  transverse  bands.  The  oblique 
ligament  (posterior  lig.  of  Winslow,  PO,  Fig.  13)  is  a  part  of  the  ten- 
dinous insertion  of  the  semimembranosus.  This  muscle  divides  into 
four  parts  at  its  insertion — one  to  the  front  of  the  tibia  in  an  arched  di- 
rection, one  straight  down  to  the  tibia,  one  to  the  popliteal  fascia,  and 
one  on  the  posterior  capsular  wall  up  and  out  to  the  outer  condyle. 
When  the  semimembranosus  tendon  is  stretched  this  oblique  ligament 
throws  the  wall  into  a  fold. 

The  arcuate  ligament  (lig.  popliteum  arcuatum,  pa)  is  comi)osed  of 
arched  fibres,  concave  upward,  springing  from  the  external  epicondyle 
and  losing  themselves  on  the  capsule  below  the  oblique  ligament.  This 
helps  form  the  opening  by  which  the  popliteal  bursa  communicates  with 
the  joint.  To  the  lower  edge  of  this  Ugament  are  inserted  a  ligament 
and  a  muscle ;  the  ligament  rises  from  near  the  apex  of  the  head  of  the 
fibula  between  the  biceps  and  soleus,  and  spreads  its  fibres  upon  both 
sides  of  the  arcuate  ligament.     It  is  the  retinaculum  lig.  arcuati  (r)  or 


THE   KNEE-JOINT. 


129 


short  external  lateral  ligament.  The  muscle,  rising  from  the  arcuate  is 
the  inner  half  of  the  popliteus.  When  the  knee  is  extended  the  reti- 
naculum is  stretched  and  the  arcuate  ligament  kept  convex :  in  the  flexed 

Fig.  13. 


ADO   MAC.> 


&EMIMEMB. 


SEMI  M  EM  B. 


PLANTARIS 


GASTROCNEMIUS 


EXT.    LAT^LIG. 

[short    EXT 
[LATUQ 


BICEPS 


SOLEUS. 


Posterior  Surface  of  Knee-joint. 


position  the  popliteus  does  the  same,  so  that  the  ligament  is  tense  in 
either  case,  and  the  canal  held  open  by  which  the  popliteal  bursa  com- 
municates with  the  joint. 

3.  Externally  is  the  long  ext.  lateral  ligament  (lig.  accessorium  laterale), 
a  flat  strand  separated  from  the  capsule  by  fat.  It  rises  from  the  exter- 
nal epicondyle,  receiving  some  fibres  from  the  external  intermuscular 
septum,  and  passes  straight  to  th^  head  of  the  fibula,  spliting  the  biceps 
tendon  at  its  insertion.  The  most  anterior  fibres  of  this  hgament  bend 
at  right  angles  to  the  front,  and  are  lost  on  the  edge  of  the  external  semi- 
lunar cartilage :  it  is  tense  in  extension  and  relaxed  in  flexion. 

4.  Internally  are  two  ligaments,  long  and  short  internal  lateral  (lig. 
access,  mediale  longum  and  breve).  Both  are  from  the  epicondyle  below 
the  lateral  patellar  ligament :  the  long  one  is  the  more  superficial  and 
attached  to  the  posterior  edge  of  the  inner  surface  of  the  tibia  2  to  3 
inches  (5-8  cm.)  below  its  articular  surface.  It  covers  the  inferior  artic- 
ular vessels  and  the  semimembranosus  tendon,  and  is  separated  by  a 
bursa  from  the  tendons  of  the  gracilis  and  semitendinosus ;  posteriorly 
it  becomes  very  thin.     As  this  rises  from  about  the  centre  of  the  circle 

9— A. 


130 


ARTICULATIONS  OF  THE  LOWER  EXTREMITY. 


formed  by  the  posterior  part  of  the  condyle,  it  has  an  equal  degree  of 
tension  in  flexion  or  extension. 

The  short  internal  lateral  ligament^  placed  behind  the  long  internal, 
is  a  continuation  of  the  semimembranosus  fibres  vertically  to  the  inner 
semilunar  cartilage. 

What  bursse  are  related  to  the  joint  ? 

Anterior  Bursce. 


Prepatellar. 

1.  Subcutaneous. 

2.  Subfascial. 

3.  Subaponeurotic. 


Pretibial. 

1.  One  in  front  of  tubercle  of 
tibia. 

2.  One  between  lig.  patellae  and 
tubercle  of  tibia. 

3.  Subpatellar. 


Suhcrural  Bursa. 
Lateral  Bursce. 


Internally. 

1.  Beneath  inner  head  of  gas- 
trocnemius. 

2.  Beneath  semimembranosus. 

3.  Between      semimembranosus 
and  semitendinosus. 


Externally. 

1.  Beneath  outer  head  of  gas- 
trocnemius. 

2.  Beneath  tendon  of  popliteus. 

3.  Between  tendon  of  popliteus 
and  ext.  lat.  lig. 

4.  Bicipital,  between  biceps,  fib- 
ula, and  ext.  lat.  lig. 

The  nerves  are  from  the  obturator,  anterior  crural,  by  branches  to  the 
vastus  externus,  internus,  and  crureus,  external  and  internal  popliteal, 
three  branches  from  each,  and  sometimes  the  great  sciatic. 

The  arteries  are — the  anastomotica  magna  of  femoral,  five  articular  of 
popliteal,  recurrent  anterior  tibial,  posterior  tibial  recurrent,  and  a  de- 
scending branch  from  the  external  circumflex. 

Movements  to  be  considered  are  those  between  each  condyle  and  tibia, 
between  femur  and  patella.  It  is  a  hinge,  and  owes  its  special  motions 
to  peculiarity  of  ligaments  rather  than  to  conformation  of  bone,  as  in 
case  of  elbow.  Flexion  and  extension  have  a  maximum  of  140° :  flexion 
is  arrested  mostly  by  the  anterior  crucial  ligament ;  the  anterior  fibres 
of  the  posterior  ligament  are  also  stretched.  At  the  beginning  of  flexion 
both  crucial  ligaments  become  relaxed :  both  are  stretched  in  extension, 
especially  the  posterior  short  fibres  of  the  posterior  crucial.  In  exten- 
sion the  lateral  ligaments  are  tense,  and  do  not  allow  any  motion  but 
flexion.  Flexion  and  extension  do  not  occur  in  a  pure  hinge-like  man- 
ner: the  same  part  of  one  articular  surface  is  not  always  applied  to  the 
same  part  of  another ;  the  axis  of  motion  is  not  a  fixed  one.   The  motion 


LIGAMENTS   BETWEEN   THE   BONES   OF   THE   LEG.        131 

.  of  the  femur  on  the  tibia  is  likened  to  that  of  a  carriage-wheel  on  the 
ground:  it  advances  or  recedes  while  it  rotates. 

The  semilunar  cartilages  are  loosely  attached,  and  move  forward  in  ex- 
tension and  backward  in  flexion  of  the  joint  like  movable  wedges ;  as  the 
condyles  roll  and  present  different  curvatures,  each  cartilage  contracts  or 
expands  to  fit  the  surface  above.  The  actual  contact  of  the  femur  with 
the  tibia  is  hardly  more  than  linear. 

In  extension  the  anterior  capsular  wall  is  raised  by  the  subcrural  mus- 
cle ;  in  flexion  the  posterior  wall  has  two  muscles  to  prevent  its  bulging- 
into  the  joint.  The  semimembranosus  acts  through  its  oblique  ligament 
when  the  flexors  from  the  thigh  and  pelvis  are  in  operation  ;  the  popli- 
teus,  through  the  arcuate  ligament  when  the  plantaris  and  those  at- 
tached to  the  OS  calcis  act. 

As  flexion  increases,  rotation  is  possible,  and  increases  to  a  total  of 
39°,  due  to  a  relaxation  of  lateral  and  crucial  ligaments.  Rotation  out 
(supination)  is  most  extensive,  as  the  external  lateral  ligaments  are  more 
loose  than  the  internal ;  this  occurs  on  an  axis  through  the  inner  condyle 
and  inner  tuberosity  of  the  tibia.  This  motion  is  checked  by  the  internal 
lateral  ligament  and  the  winding  of  the  posterior  crucial  around  the  spine 
of  the  tibia.  Rotation  in  (pronation)  on  an  axis  through  the  outer  con- 
d^de  and  outer  tuberosity  of  the  tibia  is  never  more  than  5°  or  10°;  this 
motion  is  checked  by  the  anterior  crucial  Hgament  and  by  the  twisting  of 
these  crucial  ligaments  around  each  other. 

At  the  close  of  full  extension  there  is  a  movement  of  adaptation^  or 
gliding  back  of  the  inner  condyle  upon  the  tibia :  this  axis  is  through  the 
external  condyle.  At  the  beginning  of  flexion  a  reverse  motion  takes 
place. 

The  movements  of  the  patella  are  partly  gliding  and  partly  those  of  co- 
aptation. ^  In  extension  only  the  lower  one-sixth  of  the  patellar  articular 
surface  is  in  contact  with  the  femur  ;  in  semiflexion,  the  middle  three- 
sixths  ;  in  full  flexion,  the  upper  two-sixths,  as  the  lig.  patellae  pulls  it 
down  in  front  of  the  joint. 

LIGAMENTS  BET-WEEN  THE  BONES   OF   THE  LEG-. 
Describe  the  ligaments  between  the  bones  of  the  leg. 

In  the  upper  tihio-jihular  articulation  is  a  capsule  and  two  accessory 
bands. 

The  capsule  rises  from  the  tibia  about  ^  inch  (5  mm. )  above  the  artic- 
ular surface,  elsewhere  from  its  edge ;  it  passes  to  the  contiguous  mar- 
gins of  the  fibular  surface,  and  generally  encloses  a  Httle  space  at  the 
lower  part  of  the  joint,  covered  only  by  periosteum,  where  the  tibia  and 
fibula  rest  upon  each  other. 

Accessory  hands  are  anterior  and  posterior  ligaments  (lig.  capituli 
fibulae  ant.  and  post).  The  former  consists  of  one  or  more  bands  from 
the  front  of  the  head  of  the  fibula  to  the  front  of  the  outer  tuberosity 
of  the  tibia  :  some  fibres  of  the  peroneus  longus  and  extensor  long,  digit. 


132  ARTICULATIONS   OF   THE   LOWER   EXTREMITY. 

rise  from  it.  The  posterior  ligament  connects  the  bones  in  a  similar 
manner,  and  is  covered  by  one  head  of  the  soleiis.  This  joint-cavity 
may  communicate  with  the  knee-joint.  Fat  fills  the  space  between  the 
capsule  and  interosseous  membrane. 

The  joint- surfaces  move  in  a  transverse  and  sagittal  direction,  more  in 
the  former ;  the  purpose  of  the  movement  is  to  allow  a  gliding  at  the 
lower  ends  of  the  bones. 

Between  the  bones  is  the  interosseous  ligament  or  membrane,  its  fibres 
passing  down  and  out  to  the  fibula ;  it  separates  the  flexor  from  the  ex- 
tensor muscles.  Above  is  an  opening  for  the  anterior  tibial  vessels,  and 
below  another  for  the  anterior  peroneal.  Close  to  the  upper  tibio -fibular 
joint  is  a  band  of  fibres  analogous  to  the  oblique  ligament  of  the  fore- 
arm, running  in  a  direction  opposite  to  the  fibres  of  the  rest  of  the  mem- 
brane. If  the  forearm  be  pronated  and  compared  with  the  leg,  the  two 
interosseous  ligaments  run  in  parallel  directions.  *     • 

The  inferior  tibio-fihular  joint  presents  interosseous,  anterior, posterior, 
and  transverse  ligaments.  The  interosseous  is  continuous  with  the  inter- 
osseous membrane  above.  The  anterior  and  posterior  ligaments  connect 
corresponding  surfaces  of  the  two  bones.  The  transverse  is  under  the 
posterior  ligament,  projects  below  and  connects  the  margins  of  the  bones, 
and  forms  part  of  the  articulating  surface  for  the  astragalus. 

THE  ANKLE-JOINT. 
Describe  the  ligaments  of  the  ankle-joint. 

The  ligaments  are  anterior^  posterior,  intetmal  lateral,  and  external 
lateral. 

The  anterior  is  broad  and  thin,  and  connects  the  tibia  and  astragalus. 
The  posterior  consists  mostly  of  transverse  fibres  between  the  tibia  and 
astragalus. 

The  internal  lateral  or  deltoid  has  a  superficial  and  a  deep  layer :  the 
former  rises  from  the  apex,  anterior  and  posterior  borders  of  the  internal 
malleolus,  ^  and  passes  forward  to  the  scaphoid  and  inferior  calcaneo- 
scaphoid  ligament,  downward  to  the  posterior  edge  of  the  sustentaculum 
tali,  and  backward  to  the  astragalus,  alltodifierent  bones  ;  the  deep  layer 
is  strong  and  thick,  and  passes  from  the  apex  of  the  malleolus  directly  to 
the  inner  surface  of  the  astragalus. 

^  The  external  lateral  ligament  has  three  fasciculi — one  from  the  ante- 
rior -part  of  the  external  malleolus  to  the  astragalus,  a  middle  one  from 
the  apex  of  the  malleolus  to  the  os  calcis,  and  a  posterior  one  from  the 
back  of  the  malleolus  to  the  astragalus.  (For  movements,  etc.  see  p. 
137.) 

JOINTS   OF   THE  FOOT. 
What  are  the  ligaments  of  the  tarsus  ? 

There  are  three  sets — articulations  of  first  row,  of  second  row,  of  the 
two  rows  with  each  other. 


JOINTS   OF   THE   FOOT.  133 

Those  of  the  first  row,  between  the  astragalus  and  os.  calcis,  are  exter- 
nal^ internal^  and  posterior  calcaneo-astragaloid  and  interosseous.  The 
external  is  in  front  of  and  parallel  with  the  middle  fasciculus  of  the  ext. 
lat.  lig. :  it  is  inconstant  and  connects  the  outer  surfaces  of  the  two 
hones.  The  mternal  passes  from  the  inner  tubercle  of  the  astragalus 
to  the  sustentaculum  tali.  The  posterior  is  narrow  and  connects  the 
posterior  borders  of  the  two  bones.  The  interosseous  is  thick  and  strong 
and  fills  the  groove  between  the  two  bones. 

The  ligaments  of  the  second  row  are  dorsal^  plantar^  and  four  inter- 
osseous.    These  include  the  scapho- cuboid  ligaments. 

The  ligaments  connecting  the  two  rows  are  of  three  sets — viz.  (1)  be- 
tween OS  calcis  and  cuboid  ;  (2)  between  os  calcis  and  scaphoid  ;  (3)  be- 
tween astragalus  and  scaphoid. 

(1)  Superior^  Internal,  Long  and  Short  Calcaneo-cuhoid. — The  superior 
connects  the  upper  surfaces  of  the  two  bones.  The  internal  is  some- 
what interosseous.  The  long  plantar  (long  calcaneo-cuboid)  passes  from 
the  tuberosities  of  the  os  calcis  to  the  ridge  on  the  under  surface  of  the 
cuboid,  completing  a  canal  for  the  peroneus  long,  tendon. 

The  short  plantar  extends  from  the  anterior  tubercle  of  the  os  calcis 
to  the  cuboid  behind  its  peroneal  groove. 

(2)  The  ligaments  are  superior  and  inferior  calcaneo-scaphoid.  The 
superior  and  internal  calcaneo-cuboid  form  the  arms  of  a  Y. 

The  inferior  passes  from  the  sustentaculum  tali  to  the  tuberosity  of 
the  scaphoid,  forming  an  articular  cavity  for  the  head  of  the  astragalus : 
it  is  supported  below  by  the  tibialis  posticus  tendon. 

(3)  There  is  a  thin  superior  astragalo-scaphoid  ligament :  an  inferior 
ligament  is  supplied  by  the  inferior  calcaneo-scaphoid. 

What  are  the  remaining  ligaments  of  the  foot  ? 

Tarso-metatarsal  joints  have  dorsal,  plantar^  and  interosseous  liga- 
ments: the  latter  are  three  in  number. 

The  intermetatarsal  articulations  have  dorsal,  plantar^  and  interosseous 
ligaments :  the  digital  extremities  are  united  by  a  transverse  metatarsal 
ligament  which  connects  the  great  toe  to  the  others. 

Metatarso-phalangeal  and  interphalangeal  articulations  have  each 
plantar  and  two  lateral  ligaments. 

HENLE'S    CLASSIFICATION    OF    THE    ANKLE-    AND    FOOT- 
JOINTS. 

The  articulations  of  tlie  ankle,  tarsus,  etc.  are  all  described  under  one  head, 
the  "foot-joints." 

A  division  into  capsular  membranes  and  accessory  bands  cannot  here  be 
made  just  as  in  the  hand :  a  ligament  may  pass  over  more  than  two  bones,  or 
one  connecting  two  bones  may  help  form  a  joint-socket.  There  are  three  dis- 
tinct movable  joints  to  be  considered — that  of  the  ankle,  the  anterior  and 
posterior  astragaloid  joints:  all  the  others  are  amphiarthrodial. 


134  ARTICULATIONS   OF  THE   LOWER   EXTREMITY. 

A.  Lower  Tibio-fibular  Joint. 

A  thin  capsule  is  mentioned.  Tlie  interosseous  ligament  (membrane)  ceases 
I  inch  (10  mm.)  above  the  lower  extremity  of  the  tibia:  this  distance  between 
the  tibia  and  fibula  is  a  space  hardly  deserving  the  name  "joint-cavity."  The 
tibial  surface  is  covered  with  periosteum,  the  fibular  with  a  flat  pad  of  fat 
("  valved  pad")  interposed  in  the  chink  between  the  bones.  This  allows  a 
*'give"  in  the  joint:  it  is  squeezed  up  between  the  bones  and  articulates  be- 
low with  the  supero-external  border  of  the  astragalus,  and  prevents  that  bone 
from  being  pushed  up  between  the  tibia  and  fibula. 

Accessory  bands,  anterior  and  posterior  dig.  malleoli  lateralis  ant.  and  lig. 
mal.  lat.  post.),  are  continuous  above  with  the  interosseous  ligament  and  be- 
low with  the  pufty  edge  of  the  capsule  of  the  ankle.  The  anterior  band  is 
triangular,  and  passes  down  and  out  from  the  tibia  in  front  of  its  articular 
surface  to  a  corresponding  point  on  the  fibula.  Anteriorly  it  is  covered  with 
fat  and  loose  connective  tissue:  its  posterior  surface  is  in  the  ankle-joint,  and 
its  lower  edge  overhangs  the  astragalus. 

The  posterior  ligament  resembles  the  anterior  in  shape,  but  is  stronger ;  rises 
not  only  from  the  posterior  surfaces  of  the  two  bones,  but  also  from  their  op- 
posing surfaces  and  from  a  deep  fossa  behind  the  articular  surface  of  the  fib- 
ula. These  lowest  fibres  (transverse  lig.  of  Gray)  run  to  the  inner  malleolus 
of  the  tibia  or  are  lost  on  its  posterior  capsular  wall.  Both  accessory  bands 
are  tense  in  flexion  of  the  foot  and  relaxed  in  extension. 

B.  Joints  of  the  Astragalus. 

Capsular  Ligaments. — 1.  Talo-crural  Articulation. — Talus  =  astragalus,  os  navic- 
ulare  =  scaphoid.  Surfaces  are  covered  with  hyaline  cartilage  1  to  2  mm.  thick ; 
the  accessory  bands  of  the  lower  tibio-fibular  joint  help  form  these  joint  sur- 
faces. The  upper  articular  surface  of  the  astragalus  corresponds  to  a  radius  of 
^  inch  (17  to  21  mm.)  and  an  arc  of  120°;  the  extent  of  articular  surface  on 
the  tibia  is  related  to  that  on  the  astragalus  as  2 :  3.  Both  head  and  socket  di- 
minish in  a  transverse  direction  toward  the  posterior  from  32  to  28  mm.  The 
capsule  is  tense  on  the  sides  and  loose  anteriorly  and  posteriorly,  where  it  is 
thrown  alternately  into  folds  in  flexion  or  extension  :  it  is  attached  close  to 
the  articular  surfaces  except  in  front  of  that  on  the  astragalus,  where  it  en- 
closes a  rough  space  covered  partly  by  fat  and  partly  by  thin  periosteum. 
Vertical  septa  divide  this  little  anterior  pouch  into  compartments  which  com- 
municate with  the  general  cavity  only  by  narrow  mouths.  On  the  posterior 
capsular  wall  are  hernia-like  protrusions.  The  strengthening  fibres  on  the 
posterior  wall  pass  down  and  in ;  on  the  anterior  wall  down  and  out.  Thick 
fat  pads  lie  upon  the  anterior  and  posterior  capsular  walls :  the  posterior  is 
enclosed  in  fascia  to  which  the  plantaris  is  attached,  so  that  this  pad  and  the 
capsule  are  pulled  back  when  that  muscle  contracts. 

2.  Posterior  Astragalus  Joint  (astragalo-calcanea). — The  surface  on  the  os  calcis 
is  that  of  a  cylinder  of  1^  inches  (26  mm.)  radius,  whose  axis  passes  from  the 
posterior  edge  of  the  outer  surface  of  the  bone  to  the  antero-inferior  edge  of 
the  inner,  making  an  angle  of  30°  with  the  long  axis  of  the  foot.  The  head 
of  the  joint  is  on  the  calcaneum,  the  socket  in  the  astragalus;  and  motion 
here  is  a  rotation  of  the  foot  on  its  long  axis.  The  capsular  membrane  is  close 
to  the  articular  surfaces  in  the  region  of  the  interosseous  groove,  elsewhere  is 
farther  away :  it  is  in  relation  to  fatty  masses,  especially  so  near  the  canalis 
tarsi. 

3.  Anterior  Astragalus  Joint  (astragalo-calcaneo-scaphoidea). — This  is  a  joint 
of  cylindrical  surfaces :  the  head  includes  the  anterior  surfaces  of  the  astrag- 


JOINTS   OF   THE   FOOT.  135 

alus  and  the  anterior  part  bf  its  lower  surface ;  the  socket  is  made  of  the  in- 
ner articular  surface  of  the  os  calcis,  the  posterior  surface  of  the  scaphoid,  and 
the  lig.  tibio-calcaneo-naviculare  (inferior  calcaneo-scaphoid),  and  its  fibro- 
cartilage.  A  horizontal  section  of  the  head  shows  an  arc  of  120° ;  a  vertical 
section  is  a  little  smaller.  The  lig.  tibio-calcmieo-naviculare  fills  up  the  space 
in  the  plantar  arch  on  the  inner  edge  of  the  foot  between  the  scaphoid  and 
OS  calcis :  it  is  made  up  of  fibres  which  pass  forward  from  the  groove  on  the 
astragalus  for  the  flex.  long.  poll,  tendon,  fibres  passing  down  and  forward 
from  the  tip  of  the  inner  malleolus,  down  and  back  from  the  scaphoid,  up 
and  forward  from  the  sustentaculum  tali.  At  the  junction  of  all  these  fibres 
there  is  an  elliptical  ligamentous  disk  ^  inch  (6  mm.)  thick,  hard  like  car- 
tilage, and  may  be  ossified  in  spots.  This  supports  the  head  of  the  astragalus, 
preserves  the  arch  of  the  foot,  and  forms  a  groove  for  the  tibialis  posticus 
tendon. 

The  socket  of  this  joint  presents  three  zones :  (1)  corresponds  to  the  postero- 
internal articular  surface  on  the  sustentaculum  tali ;  (2)  divided  also  into 
three  parts,  (2')  the  antero-internal  articular  surface  on  the  calcaneura,  (2") 
the  lig.  tibio-calc.-naviculare,  (2'")  the  ligamentous  disk  of  this  ligament; 
the  third  (3)  zone  is  the  anterior  wall  of  the  socket  and  belongs  to  the  sca- 
phoid. All  these  bony  surfaces  are  marked  oflT  by  deep  furrows  and  fatty 
synovial  folds.  The  joint-head  also  presents  three  zones  nearly  corresponding 
to  the  above. 

The  capsule  of  this  joint  springs  inferiorly  close  from  the  edges  of  the  artic- 
ular surfaces,  superiorly  at  some  distance  from  the  edges,  and  internally  it 
reaches  under  the  tibio-calc.-navic.  lig.  close  to  the  ankle-joint. 

Accessory  Ligaments. — Of  the  astragalus  joints  there  are  three  groups :  (1) 
those  connecting  the  astragalus  with  the  bones  of  the  leg ;  (2)  those  connect- 
ing the  astragalus  and  os  calcis ;  (3)  that  between  the  astragalus  and  scaphoid. 
The  external  are  usually  longer  and  stronger  than  the  internal. 

I.  Ligg.  Talo-cruralia. — These  pass  two  from  each  malleolus  obliquely  down 
to  the  astragalus,  one  backward  and  one  forward  on  each  side.  They  hold 
the  astragalus  so  firmly  under  the  tibia  that  no  rotation  about  a  sagittal  axis 
is  possible.  By  flexion  of  the  foot  the  two  posterior  are  stretched,  by  exten- 
sion the  two  anterior. 

1.  Lig.  Talo-fibulare  Posticum,  the  posterior  fasciculus  of  the  ext.  lat.  of 
Gray ;  origin,  fossa  on  fibula  behind  its  articular  surface ;  insertion,  posterior 
surface  of  astragalus  near  the  outer  tubercle  of  .the  flex.  long.  poll,  groove. 

2.  Lig.  Talo-tibiale  Posticum  (posterior  superficial  fibres  of  deltoid),  from 
a  little  fossa  behind  the  tip  of  inner  malleolus  to  a  smooth  place  on  the  astrag- 
alus below  the  posterior  half  of  the  joint-surface. 

3.  Lig.  Talo-fibulare  Ant.  (anterior  fasciculus  of  ext.  lat.  lig.),  external 
malleolus  to  astragalus,  10  mm.  broad;  may  divide  into  two  at  its  insertion. 

4.  Lig.  Talo-tibiale  Ant. — Short  band,  3  mm.  broad,  deeply  placed  under 
other  ligaments ;  passes  from  apex  of  inner  malleolus  to  a  point  behind  the 
rounded  apex  of  the  inner  joint-surface  of  the  astragalus. 

II.  Ligg.  Talo-calcanea. — 1.  Lig.  Talo-calcaneum  Posticum  springs  by  a  point 
from  the  outer  tubercle  of  the  flex.  long.  poll,  groove,  and  is  inserted  broadly 
or  by  two  arms  into  the  upper  and  inner  surface  of  the  os  calcis. 

2.  Lig.  Talo-calcaneum  Laterale. — Ext.  calc.-astragaloid  of  Gray ;  from  upper 
and  outer  surface  of  os  calcis,  covered  by  the  short  extensor  muscle,  passing 
through  the  fat  at  the  entrance  of  the  sinus  tarsi,  upward,  inward,  and  back- 
ward to  the  rounded  margin  of  the  astragalus,  which  overlies  the  canalis  tar- 
si.    It  is  frequently  doubled  and  frequently  lacking. 

3.  Lig.  Talo-calcaneum  Mediate,  a  small  nearly  horizontal  slip  from  the  inner 


136  ARTICULATIONS   OF  THE   LOWER   EXTREMITY. 

margin  of  the  flex.  long.  poll,  groove  to  the  posterior  edge  of  the  sustentaculum 
tali. 

4.  Lig.  Talo-calcaneum  Inter osseum  (interosseous  calcaneo-astragaloid). — This 
fills  the  tarsal  canal ;  consists  of  several  layers  and  mostly  short  fibres.  In 
the  narrowest  part  of  the  canal  two  layers  cross  each  other  obliquely. 

III.  Lig.  Talo-naviculare  are  dorsal  fibres  between  the  neck  of  the  astragalus 
and  middle  of  the  scaphoid  :  it  has  two  parts,  which  lie  beside  each  other  on 
the  astragalus  and  overlap  on  the  scaphoid,  the  external  lying  upon  the  inner 
ones,  and  some  going  on  to  the  middle  cuneiform. 

IV.  Long  Accessory  Bands  between  Bones  of  the  Leg  and  Tarsus. — 1.  Lig,  Tibio- 
naviculare  (ant.  superficial  fibres  of  deltoid),  from  the  anterior  edge  of  inner 
malleolus  down  and  out  to  the  dorsum  of  the  scaphoid. 

2.  Lig.  Calcaneo- fibular e  (middle  fasciculus  of  ext.  lat.  lig.),  from  the  apex 
of  the  external  malleolus  to  a  little  tubercle  in  the  middle  of  the  external 
surface  of  the  os  calcis :  it  is  covered  by  smooth  membrane  and  helps  form  a 
groove  for  the  peroneal  tendons :  it  may  be  doubled. 

3.  Lig.  Calcaneo-tibiale  (middle  superficial  fibres  of  deltoid),  from  inner 
malleolus  to  posterior  edge  of  sustentaculum  tali. 

C.  Amphiarthrodia  of  Tarsus. 

First  row  —  astragalus  and  os  calcis  ;  second  row  =  scaphoid  and  posterior  half  of 
cuboid  ;  third  row  =  the  cuneiform  bones  and  anterior  half  of  cuboid. 

Capsular  membranes  are  variable  in  number,  but  should  be  nine ;  they  are 
tense,  and  grow  close  to  the  edges  of  the  joint-surfaces.  The  synovial  folds 
are  fatty  and  small.  There  is  a  capsule  for  (1)  the  calcaneo-cuboid  joint;  (2) 
the  cuneo-navicular,  which  also  includes  the  articulations  of  the  cuneiform 
with  each  other,  the  external  cuneiform  with  the  cuboid,  the  navicular  with 
the  cuboid  (sometiraes) ;  (3)  tarso-metatarsal  joints:  capsules  usually  three  in 
number — one  for  the  internal  cuneiform  and  first  metatarsal,  one  for  the  mid- 
dle and  external  cuneiform  and  second  and  third  metatarsals,  the  third  for 
the  cuboid  and  fourth  and  fifth  metatarsals. 

Accessory  Bands  of  Tarsus. — I.  On  Dorsal  Surface. — 1.  Transverse :  (a)  in  sec- 
ond row,  ligg.  naviculari-cuboidea,  a  superficial  and  a  deep  one;  (&)  in  third, 
row,  (1)  ligg.  cuneo-cuboid.,  an  anterior  and  a  posterior  one ;  (2)  between  second 
and  third  cuneiforms;  (3)  between  second  and  first,  (c)  In  the  metatarsus, 
ligg.  intermetatarsea  dorsalia,  lacking  between  the  first  and  second. 

2.  Sagittal :  (a)  between  first  and  second  rows,  (1)  lig.  calcaneo-naviculare  dor  sale 
=  superior  calcaneo-scaphoid ;  (2)  ligg.  calcaneo-cuboidea  dorsalia,  two  or  three 
bands  =  superior  and  internal  calcaneo-cuboid ;  (6)  between  second  and  third 
rows,  (1)  between  scaphoid  and  outer  cuneiform;  (2)  scaphoid  and  middle 
cuneiform,  two  bands ;  (3)  scaphoid  and  inner  cuneiform,  two  strong  bands ; 
(c)  between  third  row  and  metatarsus,  ligg.  tarso-metatarsea  dorsalia;  one  to 
the  first  metatarsal  from  the  internal  cuneiform;  three  to  the  second,  one 
from  each  cuneiform ;  to  the  third  are  variable  bands,  may  be  two  from  the 
two  outer  cuneiform ;  to  the  fourth,  one,  sometimes  two,  from  the  cuboid ;  to 
the  fifth,  one  from  the  cuboid. 

II.  Accessory  Bands  of  Plantar  Surface. — There  are  long  bands  which  are 
superficial  and  pass  over  several  bones ;  short  bands  which  are  deep  and  con- 
nect adjoining  bones,  {a)  Long  Ligaments. — Lig.  calcaneo-cuboideum  plantare  = 
plantar  ligaments  of  Gray.  This  rises  from  the  whole  rough  under  surface 
of  the  OS  calcis  from  the  two  posterior  tubercles  to  the  anterior  one :  it  is 
divisible  into  three  layers.  The  most  superficial  passes  over  the  tuberosity 
of  the  cuboid  to  the  flexor  brevis  poll,  muscle,  to  the  interossei  and  bases  of 
the  metatarsal.    These  last  fibres  are  strengthened  by  single  bundles  rising 


JOINTS   OF   THE  FOOT.  137 

from  the  tuberosity  of  the  cuboid :  the  fibres  to  the  flexor  brevis  poll,  are 
joined  by  transverse  fibres  from  the  tendon  of  the  tibialis  posticus,  and  are 
also  connected' with  the  plantar  fascia. 

The  middle  set  of  fibres  extends  to  the  tuberosity  of  the  cuboid.  The 
deepest  set  is  inserted  into  the  cuboid  behind  its  tuberosity,  passing  mostly 
from  the  anterior  tubercle  of  the  os  calcis :  it  comes  to  view  internal  to  the 
upper  layers. 

The  lig.  tarseum  transversum  laterale  goes  from  the  external  cuneiform,  cov- 
ered by  the  peroneus  longus  tendon,  to  the  tuberosity  of  the  fifth  metatarsal. 

The  lig.  tarseum  transversum  mediale  runs  from  the  inner  surface  of  the  inner 
cuneiform  to  the  base  of  the  third,  sometimes  fourth,  metatarsal. 

{b)  Short  Ligaments. — 1.  Transverse:  (a)  in  second  row,  lig. cuboideo-naviculare 
plantare;  (&)  in  third  row,  between  the  cuboid  and  outer  cuneiform  and  be- 
tween the  cuneiforms  is  a  continuous  band  or  several  separate  ones ;  (c)  in  the 
metatarsus,  ligg.  intermetatarsea  plantaria,  only  between  the  four  outer  bones : 
the  lack  of  one  between  the  first  and  second  is  supplied  by  a  band  from  the 
internal  cuneiform  to  the  base  of  the  second. 

2.  Sagittal :  (a)  between  first  and  second  rows,  lig.  calcaneo-naviculare  plan- 
tare,  a  short  round  band  running  obliquely  inward  and  forward  to  the  navic- 
ular bone  from  ^the  anterior  inner  corner  of  the  os  calcis ;  (b)  between  the 
second  and  third  rows,  from  the  scaphoid  to  the  cuneiforms,  a  broad  band 
covered  by  the  tibialis  posticus  tendon ;  (c)  between  the  third  row  and  meta- 
tarsus, ligg.  tarso-metatarsea  plantaria,  a  broad  and  strong  band  to  the  first  from 
the  inner  cuneiform;  weak  bands  to  the  second  from  the  middle  and  outer 
cuneiforms;  to  the  third,  short  bands  from  the  middle  and  external  cunei- 
forms and  cuboid ;  to  the  fourth,  a  band  from  the  outer  cuneiform  or  from 
the  cuboid,  or  from  both. 

3.  Accessory  Bands  in  the  Interspaces  of  the  Metatarsus. — Ligg.  intermetatarsea 
interossea  lie  in  the  spaces  just  in  front  of  the  capsules  in  which  the  side  sur- 
faces of  the  bases  of  the  metatarsals  articulate  with  each  other. 

What  separate  synovial  cavities  are  there? 

Usually  six — one  for  the  posterior  calcaneo-astragaloid  joint;  one  for  the 
anterior  and  the  astragal  o-scaphoid  joint;  one  for  the  calcaneo-cuboid ;  one 
for  the  cuneo-scaphoid,  the  cuneiform  with  each  other,  the  external  cunei- 
form with  the  cuboid,  the  middle  and  external  cuneiform  with  the  second 
and  third  metatarsals ;  one  for  the  first  metatarsal  and  internal  cuneiform  ; 
one  for  the  fourth  and  fifth  and  cuboid  ;  sometimes  one  between  the  scaphoid 
and  cuboid. 

Nerves  for  ankle-joint  proper  are  from  anterior  and  posterior  tibials  :  tarsal 
joints  have  the  anterior  tibial  and  plan  tars. 

Arteries  of  ankle  are  anterior  and  posterior  tibials,  anterior  and  posterior 
peroneals;  lower  down  are  the  plantars  and  dorsalis  pedis. 

The  movements  of  the  ankle-joint  are  flexion  and  extension — a  little  lateral 
motion  in  extension :  this  is  possible  because  the  astragalus  and  tibio-fibular 
mortise  are  a  little  wider  in  front  than  behind,  and  in  extension  the  nar- 
rowest part  of  the  astragalus  is  in  the  widest  of  the  articular  socket.  *  In 
flexion,  as  in  stepping  upon  a  chair,  where  lateral  motion  would  be  dan- 
gerous, the  two  joint-surfaces  fit  closely.  With  flexion  is  associated  a  slight 
rotation  out  of  the  foot;  with  extension,  a  slight  rotation  in.  Flexion,  a 
lifting  of  the  apex  of  the  foot,  is  possible  to  20°  from  the  horizontal ;  exten- 
sion, a  depression  of  the  apex  of  the  foot,  goes  through  45°. 

Eversion  or  inversion  of  the  foot  means  a  rotation  out  or  in  of  the  whole 
lower  extremity.    Rotation  out  or  in  is  rotation  of  the  whole  foot  on  a  longi- 


138  MYOLOGY. 

tudinal  axis:  this  occurs  at  the  posterior  calcaiieo-astragaloid  joint.  The 
foot  is  rotated  in  when  the  sole  looks  in.  Adduction  or  abduction  refers  to  a. 
displacement  in  or  out  of  the  fore-foot,  motion  occurring  in  the  tarsal  joints, 
especially  mid-tarsal. 

The  movements  between  the  lower  ends  of  the  tibia  and  fibula  are  those  of 
elasticity. 

What  are  the  ligaments  of  the  metatarso-phalangeal  joints  ? 

Each  has  a  capsule,  which  is  connected  with  the  other  by  ligg.  capitulorum 
plantaria  and  dorsalia,  which  together  form  the  transverse  metatarsal  liga- 
ment of  Gray.  It  connects  the  great  toe  with  the  others.  Under  the  joints 
it  is  developed  into  a  thick  fibrous  or  sesamoid  plate.  In  the  one  for  the  great 
toe  the  plate  is  ossified  into  two  bones  held  together  by  transverse,  bands : 
this  may  occur  in  other  toes.  Besides  the  above  there  are  two  lateral  liga- 
ments. As  a  rule,  there  is  a  bursa  between  the  capsules  in  the  three  inner 
intermetatarsal  spaces. 

The  interphalangeal  articulations  are  practically  the  same  as  those  of  the 
fingers. 


MYOLOGY. 

How  are  muscles  divided? 

Into— 

I.  Voluntary,  striated  (animal  life) ; 

IT.  Involuntary  (vegetative  life) — (a)  smooth,  non-striated,  (Z))  striated 
(cardiac). 

Describe  the  structure  of  muscle. 

I.  Primitive  muscle  Jihrillce  form  fibres ;  fibres,  fasciculi;  fasciculi, 
muscles  or  flesh. 

Epimysium  surrounds  entire  muscle,  and  sends  partitions  between  fas- 
ciculi, called  perimysium ;  endomysium  is  between  the  fibres,  but  not  as 
a  sheath.  ^  • 

The  fibres  average  ^^  inch  in  diameter,  1 }  inches  long  ;  by  volition 
may  contract  one-fourth  or  one-third  of  its  length,  by  electricity  three- 
fourths.  They  consist  of  (1)  central  contractile  substance,  (2)  nuclei,  (3) 
tubular  sheath  or  sarcolemma:  they  are  divisible  into  the  primitive 
fibrillas,  shown  by  longitudinal  striations,  and  each  fibrilla  breaks  into 
disks  called  sarcous  elements^  dark  in  the  centre,  with  a  lighter  zone  at 
each  end ;  transversely  through  the  light  zone  passes  Kranses  line,  or 
membrane  limiting  with  the  sarcolemma  each  element ;  Hensen^s  line 
passes  transversely  through  the  central  dark  band. 
^  Striated  muscles  comprise  those  of  locomotion,  respiration,  expres- 
sion ;  those  of  ear,  larnyx,  pharynx,  tongue,  upper  half  of  oesophagus, 
and  walls  of  large  veins  near  heart. 

II.  [a]  Smooth,  unstriped  muscular  fibres  are  made  up  of  long  nu- 
cleated cells,  collected  in  bundles  or  layers,  surrounded  by  connective 
tissue;  the  cell-body  shows  a  longitudinal  striation.     This  variety  of 


PLATE  IX. 

Fig.  1 .  -—  To  fme  page  138. 


Arrangement  of  Muscular  Fibres  in  Muscles  in  relation  to  the  tendons 
and  muscular  aponeuroses:  t,  t^,  tendons  of  origin  and  insertion;  My 
muscular  belly ;  a,  6,  length  of  muscular  belly  (Beaunis  and  Bouchard). 

Fig.  2. — To  face  page  146. 


A  Transverse  Section  of  the  Abdomen  in  the  Lumbar  Region. 


PLATE  X. 

Fig.  1. — To  face  page  152. 


■Superficial  perineal  artery. 
Superficial  perineal  nerve. 
Internal  pudic  nerve. 
Internal  pudic  artery. 


The  Superficial  Muscles  and  Vessels  of  the  Perinseum. 


Fig.  2. — To  face  pages  158  and  159. 
A  Jaw.  B 


Trapezius. 


Median  line. 


C  Cla^dcle.  D 

Diagram  of  the  Triano'les  of  the  Right  Side  of  the  Neck. 


MUSCLES  OF   THE   TRUNK.  139 

muscle  is  found  in  the  lower  part  of  the  oesophagus,  stomach,  intestinal 
canal,  spleen,  trachea,  bronchial  tubes,  gall-bladder,  bile-duct,  ducts  of 
large  glands,  of  sweat-glands,  uterus,  appendages,  vagina,  ureters,  blad- 
der, urethra,  corpora  cavernosa,  dartos,  epididymis,  prostate,  ciliary 
muscle,  iris,  coats  of  veins,  arteries,  and  lymphatics,  (b)  In  striated 
heart-muscle  the  fibres  anastomose  and  form  a  long-meshed  network ; 
no  sarcolemma:  transverse  striae  are  weak,  fibres  small,  and  made  up 
of  quadrangular  cells  joined  end  to  end,  each  with  a  central  nucleus. 

MUSCLES  IN  GENERAL. 

They  are  symmetrical  in  pairs,  excepting  the  sphincters  and  a  few 
others.  They  number  about  31 1  (voluntary) :  head  and  front  of  neck  = 
82,  vertebral  column  and  back  of  neck  =  60,  thorax  =  42,  abdomen  =  14, 
upper  hmb  =  59,  lower  limb  =  54.  If  a  man  weighs  150  pounds,  his 
skeleton  weighs  28  pounds ;  muscles,  62  pounds  (over  40  per  cent. ) ;  vis- 
cera, fat,  blood,  etc.,  60  pounds. 

How  are  muscles  named? 

(1)  From  situation^  as  tibialis  ;  (2)  direction^  rectus ;  (3)  use^  flexors ;  (4) 
shape,  deltoid ',  (5)  subdivision,  biceps ;  (6)  attachment,  sterno-cleido- 
masto-occipitoid  ;  (7)  size,  magnus;  (8)  bellies,  digastric;  (9)  structure, 
semimembranosus;  ('[0)  relation  to  organs,  extrmsiG  or  intrinsic ;  (11) 
position,  superficial  or  deep  ;  (12)  name  of  describer,  Horner's,  Galen's. 

Some  muscles  are  synergists  to  others,  some  antagonists,  some  mode- 
rators. 

The  origin  of  a  muscle  refers  to  its  more  fixed,  the  insertion  to  its  more 
movable  or  remote,  attachment.  The  same  nerves  that  supply  joints  gen- 
erally supply  the  muscles  and  integument  over  those  joints. 

How  are  fasciae  arranged? 

The  superficial  fascia  is  subcutaneous  all  over  the  body :  its  web  con- 
tains subcutaneous  fat,  the  panniculus  adiposus,  and  often  superficial 
muscles,  the  panniculus  carnosus.  There  is  no  fat  in  this  layer  in  the 
eyelids,  penis,  and  scrotum.  Beneath  the  fatty  layer. is  usually  another, 
devoid  of  fat,  for  the  support  of  vessels  and  nerves. 

The  deep  fasciae  or  aponeuroses  are  made  of  strong  fibrous  tissue  cov- 
ering the  body  more  or  less,  forming  aponeuroses  of  investment  or  of  in- 
sertion for  muscles.  Near  some  joints  it  is  strengthened  by  transverse 
bands,  forming  retinacula  or  annular  ligaments  to  hold  tendons  close  to 
bone. 

MUSCLES  OP  THE  TRUNK. 

MUSCLES  AND  FASCIA   OP   THE  BACK. 

Describe  the  muscles  of  the  back. 

(a)  Superficial,  running  out  from  spinous  processes. 

First  Layer. — Musculus  Trapezius  (cucullaris),  or  hood  muscle. — 


140  MUSCLES   OF   THE  TRUNK. 

Origin^  inner  third  superior  curved  line  of  occipital  bone,  lig.  nuchas, 
spinous  processes  of  the  seventh  cervical,  and  all  the  dorsal  vertebrae  and 
supraspinous  ligament ;  insertion^  fibres  converge  to  shoulder  girdle ; 
superior  ones  to  outer  third  or  half  of  posterior  border  of  clavicle  ;  mid- 
dle fibres  horizontally  to  inner  margin  of  acromion  and  superior  lip  of 
scapular  spine  ;  inferior  fibres  up  and  out  to  a  triangular  tendon  gliding 
over  the  inner  extremity  of  the  spine  and  inserted  into  a  tubercle  at  its 
lower  posterior  margin.  The  aponeuroses  of  the  .two  muscles  form  an 
ellipse  widest  at  the  seventh  cervical  spine. 

Varieties. — May  not  rise  from  lower  six  dorsal  spines ;  no  occipital  attach- 
ment ;  separation  of  cervical  and  dorsal  parts ;  vestige  of  panniculus  carnosus 
superficial  to  it. 

^  Second  Layer. — 1.  M.  Rhomboideus  Minor. — Origin^  seventh  cer- 
vical and  first  dorsal  spines  and  lig.  nuchas  of  that  region ;  insej^tion, 
base  of  scapula  opposite  triangular  surface  at  commencement  of  spine. 

2.  M.  Rhomboideus  Major.  —  Origin,  spinous  processes  of  four  or  five 
upper  dorsal  vertebrae  and  supraspinous  ligament ;  insertion,  base  of 
scapula  between  spine  and  inferior  angle.  The  greater  part  of  its  fibres 
is  not  fixed  directly  to  bone,  but  ends  in  a  tendon  attached  to  the  lower 
angle  of  the  scapula,  so  that  the  muscle  acts  more  especially  upon  this 
angle. 

This  muscle  comes  to  view  in  the  sixth  intercostal  space,  with  the  scapula 
external,  trapezius  internal,  and  latissimus  dorsi  below.  Variable  in  verte- 
bral and  scapular  attachments ;  the  division  between  the  two  indistinct.  M. 
rhomboideus  occipitalis  (occipito-scapularis)  above  rhomb,  min.  from  occiput 
beneath  splenius  to  scapula,  covering  insertion  of  rhomb,  min.,  normal  in 
rabbits. 

3.  31.  Teres  Major,  not  round. —  Origin,  dorsal  aspect  inferior  angle 
of  scapula,  slightly  from  axillary  border,  from  septa  between  it,  the 
minor  and  infraspinatus,  from  infraspinatus  fascia;  insertion,  by  flat 
tendon,  2  inches  wide,  behind  latissimus  dorsi  into  inner  bicipital  ridge 
of  humerus.  The  two  tendons  are  united  below  for  a  short  distance, 
but  separated  by  a  bursa  at  their  insertion. 

May  be  connected  with  latissimus  dorsi  where  it  rises  from  the  scapula ;  a 
slip  to  the  fascia  of  the  upper  arm  externally. 

4.  M.  Latissimus  Dorsi,  broad  and  flat  at  its  origin,  narrow  at  its  in- 
sertion.—  Origin,  spinous  processes  of  lower  six  or  seven  dorsal  ver- 
tebrae, posterior  layer  of  lumbar  aponeurosis,  which  attaches  it  to  the 
lumbar  and  sacral  spines  and  iUac  crest,  from  external  lip  of  iliac  crest 
in  front  of  lumbar  aponeurosis ;  from  last  three  or  four  ribs  by  digita- 
tions  interposed  between  those  of  the  external  oblique ;  usually  by  a  slip 
from  inferior  angle  of  scapula.  Its  upper  fibres  are  nearly  horizontal, 
middle,  oblique,  and  lower,  vertical :  it  winds  round  the  teres  major  and 
in  front  of  it,  and  is  inserted  by  a  tendon  1}  inches  wide  into  floor  of  bi- 
cipital groove,  a  little  higher  than  the  teres  major,  and  by  its  upper  edge 


MUSCLES   AND   FASCIA   OF   THE   BACK.  141 

into  the  inner  lip  of  the  groove  limiting  the  insertion  of  the  subscap- 
ularis. 

Vertebral  and  costal  attachments  variable ;  muscular  bands,  axillary  arches 
from  near  the  insertion  across  the  great  vessels  and  nerves  to  either  the  great 
pectoral  tendon,  coraco-brachialis,  biceps,  or  fascia;  a  slip  from  lower  ribs  to 
coracoid  =  m.  costo-coracoid  ;  a  slip  to  triceps,  fascia,  or  internal  intermuscular 
septum  =  m.  dorso-epitrochlearis  of  apes,  usually  present  in  man  as  a  fibrous 
band. 

Third  Layer. — Serrati  Muscles. — 1.  M.  Serratus  Posticus  Superior. 
—  Origin^  by  a  thin  aponeurosis  from  two,  rarely  three,  upper  dorsal 
spines,  supraspinous  ligament,  seventh  cervical  spine,  lower  part  of  lig. 
nuchge ;  fibres  pass  down  and  out ;  inserted  by  four  slips  into  the  upper 
borders  and  outer  surfaces  of  the  second,  third,  fourth,  and  fifth  ribs 
beyond  their  angles. 

The  slips  may  be  three  or  increased  to  six. 

2.  M.  Serratus  Post.  Inferior^  broader  than  the  above. — Origin.,  by 
part  of  the  lumbo-dorsal  aponeurosis  from  first  two  lumbar  and  last  two 
or  three  dorsal  spines ;  passing  up  and  out ;  inserted  by  four  slips  intx) 
the  lower  borders  of  the  last  four  ribs  up  to  the  origin  of  the  lat.  dorsi. 

The  two  middle  slips  are  broadest ;  the  others  may  be  lacking ;  they  over- 
lap each  other  from  above. 

Fourth  Layer. — Mm.  Splenii. — Named  from  strap-like  action  bind- 
ing down  underlying  parts ;  rise  from  lower  half  of  neck  and  upper  half 
of  back. 

1.  M.  Splenms  Capitis. — Origin^  lig.  nuchse  over  third,  fourth,  fifth, 
and  sixth  cervical  spines,  from  seventh  cervical  and  first  two  dorsal 
spines ;  insei^tion^  outer  surface  and  posterior  margin  of  mastoid  process, 
outer  part  of  superior  curved  line  to  insertion  of  trapezius. 

2.  31.  Splenitis  Cervicis  (colli). — Origin^  below  the  above  from  third, 
fourth,  fifth  dorsal  spines,  not  lower  than  the  sixth ;  insertion^  with  slips 
of  levator  ang.  scap.  into  tips  of  trans,  proc.  of  first  and  second,  often 
third,  cervical  vertebras. 

The  splenii  are  covered  in  part  by  the  trapezius,  rhomboidei,  and  superior 
serratus ;  the  complexus  comes  to  view  internal  to  them.  The  m.  rhombo- 
atloideus,  or  splenius  colli  access.,  rises  from  the  lower  one  or  two  cervical  spines 
superficial  to  the  superior  serratus,  inserted  into  the  trans.* proc.  of  the  atlas. 
M.  splenius  capitis  access,  is  a  similar  slip  ending  on  the  occipital  bone  or 
mastoid. 

iVerves.— Trapezius  by  spinal  accessory,  third  and  fourth  cervical  n. ;  rhom- 
boidei by  fifth  cerv.  n. ;  teres  major  by  lower  subscapular  n.  (6,  7  c.) ;  latissi- 
mus  dorsi  by  long  subscapular  n.  (7,  8c.);  serrati  by  intercostals  or  upper  slip 
of  ser.  post.  sup.  by  cervical  plexus ;  splenii  by  posterior  spinal  n. 

Actions. — Trapezius,  upper  part  supports  shoulder,  raises  point  of  shoulder 
by  rotation  of  scapula,  acts  in  forced  respiration ;  middle  part  adducts  scap- 
ulae, helps  elevate  shoulder,  throws  chest  out ;  inferior  part  would  alone  de- 
press and  carry  scapulee  in,  but  in  concert  with  the  upper  two-thirds  of  the 


142  MUSCLES   OF   THE   TRUNK. 

muscle  it  raises  acromion  and  carries  lower  angle  out  and  up.  Fixed  below, 
one  acting,  draws  head  back  and  rotates  face  to  opposite  side ;  both  acting, 
draw  head  back.  The  rhomboidei  are  special  antagonists  of  the  serratus  mag- 
nus ;  they  elevate  the  superior  angle  of  the  scapula  and  counteract  the  rota- 
tion of  the  trapezius;  combined  with  the  trapezius,  the  scapula  is  raised 
without  rotation  or  drawn  back  and  in.  Teres  major,  fixed  at  humerus, 
rotates  scapula;  fixed  at  scapula,  rotates  raised  humerus  in  and  depresses 
arm.  Latissimns  dorsi,  fixed  at  humerus,  draws  body  forward  as  in  using 
crutches  or  climbing,  feebly  in  forced  respiration ;  fixed  below,  carries  ele- 
vated arm  down,  back,  and  rotates  in ;  draws  shoulder  down  and  back ;  is 
used  in  swimming;  keeps  inferior  angle  of  scapula  close  to  chest-wall. 

Serratus  post,  sup.,  muscle  of  forced  inspiration ;  serratus  post,  inf.,  muscle 
of  forced  expiration  (Quain  says  of  inspiration,  as  it  holds  the  lower  ribs  fixed 
when  the  diaphragm  tends  to  draw  them  up). 

Splenii  of  one  side  draw  head  and  neck  back  and  rotate  face  to  same  side ; 
help  keep  head  erect. 

What  are  the  dorsal  and  lumbar  fasciae  ? 

The  vertebral  aponeurosis  represents  the  middle  portion  of  the  muscu- 
lar sheet  of  the  serrati ;  above,  it  passes  beneath  the  superior  serratus ; 
below,  it  is  blended  with  the  lat.  dorsi  and  inferior  serratus,  and  binds 
down  the  long  extensor  muscles.  The  lumbar  aponeurosis  is  usually 
described  in  three  layers,  enclosing  the  erector  spinae  and  quad,  lumbo- 
rum:  its  posterior  layer  is  continuous  with  the  vertebral  aponeurosis, 
and  by  it  the  lat.  dorsi  and  inferior  serratus  are  attached  to  the  vertebral 
spines. 

(h)  Deep  Longitudinal ^  Muscles.— Lo^G  Muscles. — 1.  M.  Sacro- 
spinalis,  p.  n.*  (erector  spinas). — Origin,  lowest  two  or  three  dorsal,  all 
the  lumbar  and  sacral  spines,  posterior  fifth  of  inner  lip  of  iliac  crest, 
lower  and  back  part  of  sacrum,  anterior  surface  of  lumbar  fascia :  oppo- 
site the  last  rib  this  mass  divides  into  middle  and  outer  columns,  and  an 
inner  one,  spinalis  dorsi,  separates  from  the  middle  in  the  upper  dorsal 
region.     The  outer  and  middle  portions  subdivide. 

Middle. Portion.  Outer  Portion. 

Longissimus    dorsi    (Longissimus  Sacro-lumbalis  (Ilio-costalis  lum- 

dorsi,  p.  w.).       ^^               ^    ^  borum,  _p.  ?!.). 

Transversalis^  cervicis    (Longissi-  Accessorius  (Ilio-costalis  dorsi,  p. 

mus  cervicis,  p.  71.).        ^    ^  n.).     ^ 

Trachelo-mastoid       (Longissimus  Cervicalis  ascendens   (Ilio-costahs 

capitis,  p.  n.).  cervicis,  p.  ?i. ). 

M.  ilio-costalis  lumhorum  (sacro-lumbalis),  from  outer  and  superficial 
portion  of  common  mass  into  angles  of  lower  six  or  seven  ribs. 

31.  ilio-costalis  dorsi  ( acce.ssor ius ), /rom  ribs  into  which  the  preceding 
is  inserted,  but  internal  to  it,  into  angles  of  the  upper  six  ribs  and  trans, 
proc.  of  the  seventh  cerv.  vert. 

*  A  commission  of  anatomical  nomenclature  has  suggested  for  universal  use 
names  here  marked  p.  n.  (proposed  name).  It  is  practically  the  nomenclature 
of  Henle. 


MUSCLES   AND    FASCIA   OF   THE   BACK.  143 

M.  ilio-costalis  cervicis  (cervicalis  ascendens)  continues  the  series  from 
angles  of  upper  four  or  five  ribs  into  posterior  tubercles  of  fourth,  fifth, 
and  sixth  cerv.  trans,  proc. 

M.  longissimus  dorsi  rises  from  common  mass,  has  two  sets  of  inser- 
tions— an  inner  row  of  round  tendons  into  all  the  dorsal  trans,  proc.  and 
lumbar  accessory  proc.  ;  an  outer  row  to  the  lowest  nine  or  ten  ribs  be- 
tween angles  and  tuberosities,  and  to  whole  length  of  lumbar  trans,  proc. 
and  into  lumbar  fascia. 

M.  longissimus  cervicis  (transversalis  cerv.),  from  highest  four  or  five 
dorsal  trans,  proc.  into  posterior  tubercles  of  trans,  proc.  of  five  cerv. 
vert. ,  second  to  sixth  inclusive. 

M.  longissimus  capitis  (trachelo-mastoid),  by  four  tendons  from  the 
upper  dorsal  trans,  proc. ,  and  from  articular  proc.  of  the  lower  three  or 
four  cervical  vert.,  into  the  posterior  margin  of  the  mastoid  process 
under  the  splenius  cap.  and  sterno-mastoid.  It  shows  a  tendinous  inter- 
section near  its  insertion :  it  is  the  only  muscle  between  the  splenius  and 
complexus. 

2.  Musculi  spinales,  spinous  muscles,  have  an  arched  direction.  (1) 
M.  spinalis  dorsi,  close  inside  the  longissimus  dorsi  and  connected  with 
it ;  origin,  lowest  two  or  three  dorsal  spines  and  from  tendons  passing 
from  upper  lumbar  spines  to  long,  dorsi ;  inserted  by  four  to  nine  slips 
into  the  upper  dorsal  spines. 

(2)  M.  spinalis  cervich,  inconstant  or  difi*erent  on  the  two  sides /rom 
lig.  nuchas  and  seventh  cerv.  spine,  and  one  or  two  above  or  below  this ; 
inserted  into  spine  of  axis  or  also  into  third  and  fourth  cervical  spines. 

M.  sacro-coccygeus  posticus,  or  extensor  coccygis  (rare),  from  lower  end  of 
sacrum  to  coccyx,  represents  a  strong  extensor  of  lower  animals. 

3.  M.  transverso-spinalis,  a  common  name  for  a  group  all  inclined  in- 
ward from  transverse  to  spinous  processes. 

[a)  Mm.  Seftnispinales  (half-spinous). — (1)  M.  semispinalis  dorsi,  hy 
five  or  six  tendons  from  the  trans,  proc.  of  the  dorsal  vert. ,  from  the 
sixth  to  the  tenth,  inclusive ;  inserted  by  just  as  many  tendons  into  the 
spines  of  the  upper  four  dorsal  and  lower  two  cervical  vert.  (2)  M.  semi- 
spinalis  ca^vicis,  covered  by  the  complexus,  rises  nearly  from  the  inser- 
tion vertebrae  of  preceding — viz.  upper  five  or  six  dorsal  trans,  proc.  ; 
inserted  into  cervical  spines  from  second  to  fifth,  inclusive,  being  thickest 
into  the  axis.  (3)  M.  semispinalis  capitis  (complexus)  rises  by  two  sets 
of  heads :  the  inner,  or  hiventer  cervicis,  rises  from  three  or  four  dorsal 
trans,  proc.  between  the  second  and  sixth ;  its  superficial  fibres  are  in- 
serted into  the  external  occipital  protuberance  beside  the  lig.  nuchas ;  its 
deeper  fibres  join  the  external  head.  The  outer  head  iv'ses  from  upper 
dorsal  and  lower  three  or  four  cervical  vert.,  on  the  dorsal  and  seventh 
cerv.  from  trans,  proc,  on  the  remaining  cerv.  vert,  (fourth,  fifth,  or 
sixth)  by  two  slips  from  each,  one  from  the  posterior  tubercle  of  the 
trans,  proc,  and  one  from  the  lower  articular  process.  These  fibres 
unite,  join  part  of  the  inner  head,  and  are  inserted  into  the  inner  im- 


144  MUSCLES  OF  THE   TRUNK. 

pression  between  the  two  curved  occipital  lines.  A  tendinous  inscrip- 
tion crosses  the  muscle  near  the  spine  of  the  axis  ;  another  crosses  the 
biventer  lower  down. 

(b)  M.  multifidus  (spinas)  occupies  the  groove  beside  the  spinous  pro- 
cesses from  the  sacrum  to  the  axis;  rises  from  deep  surface  of  erector 
spinge,  from  back  of  sacrum  as  low  as  fourth  foramen,  posterior  extrem- 
ity of  ilium,  and  posterior  sacro-iliac  ligament ;  in  lumbar  region  from 
mammillary  processes;  in  dorsal,  from  trans,  proc;  in  cervical,  from  ar- 
ticular processes  of  the  four  lower  vert.  The  bundles  pass  up  and  in,  to 
be  inserted  into  the  whole  length  of  the  spines  from  the  last  lumbar  to 
the  axis :  some  fibres  go  to  the  fourth  vertebra  above,  others  to  those 
nearer. 

(c)  Mm.  Rotator es. — (1)  Mm.  rotator es  longi^  really  a  part  of  the  mul- 
tifidus, only  in  dorsal  region,  from  upper  edge  of  a  trans,  proc.  to  lateral 
edge  of  root  of  the  second  or  third  spinous  process  above. 

(2)  Mm.  rotatores  breves  (rotatores  dorsi  of  Quain),  eleven  in  number, 
dorsal  region,  nearly  horizontal,  from  upper  edge  of  a  trans,  proc.  to 
lower  edge  of  the  lamina  above. 

Short  Muscles. — All  those  connecting  adjacent  vertebrae. 

1.  Of  Flexion-vertebrce. — 1.  Mm.  inter spinales,  vertical  sets  of  fibres 
in  pairs  between  contiguous  spinous  processes  ;^  in  the  neck  they  are 
round,  in  the  back  are  usually  absent,  in  the  loins  are  flat  from  side  to 
side. 

2.  Mm.  Intertransversales  (posterior,  as  there  is  also  an  anterior  set  in 
the  neck). — In  the  lumbar  region  there  are  two  parts — an  inner,  inter- 
transversalis  post,  medialis,  from  a  mammillary  process  to  an  accessory 
or  mammillary  process  next  above ;  an  external,  intertr.post.  lateralis^ 
between  two  contiguous  trans,  proc.  In  the  back  the  inner  portion  is 
supplied  by  the  intertransverse  ligaments,  the  outer  portion  by  the  lev. 
costarum ;  in  the  neck  and  upper  dorsal  region  they  are  single  bands  be- 
tween the  trans,  proc.  and  behind  the  cervical  nerves. 

3.  Mm.  levatores  costarum^  twelve  on  either  side,  i^se  from  the  tips 
of  the  trans,  proc.  of  the  seventh  cervical  and  upper  eleven  dorsal  vert. ; 
continued  externally  into  the  external  intercostals,  and  inserted  into  the 
outer  surface  of  the  rib  belonging  to  the  vertebra  below  that  from  which 
it  springs,  between  the  tuberosity  and  angle.  Those  muscles  passing  to 
the  adjacent  rib  are  lev.  cost,  breves :  in  the  lower  dorsal  region  are  lev. 
cost,  longi,. which  pass  over  one  rib. 

II.  Short  Muscles  of  Rotation-vertebrce  and  Occiput. — Five  on  each 
side ;  two  rise  from  the  axis  and  three  from  the  atlas.  1.  M  rectus  cap- 
itis posticus  major. —  Origin^  spine  of  axis,  upper  border;  iyisertion^  into 
and  below  the  middle  third  of  the  inferior  curved  line  of  the  occiput. 
2.  M.  obliquns  cap.  inferior^  strongest  of  these  muscles. — Origin^ 
upper  and  posterior  part  of  arch  of  axis  (Henle) ;  insertion,  back  part 
of  trans,  proc.  of  atlas.  3.  M.  rectus  cap.  post,  rninor.— Origin,  poste- 
rior tubercle  of  atlas ;  insei'tion,  into  and  beneath  inner  third  of  inferior 
curved  line  of  occiput,  covered  partly  by  the  major  muscle.     4.  31. 


MUSCLES   AND    FASCIA   OF   THE   ABDOMEN.  145 

ohliqum  cap.  superior. — Origin^  upper  surface  of  trans,  proc.  of  atlas; 
insertion.,  impression  between  outer  parts  of  the  occipital  curved  lines. 
5.  M.  rectus  cap.  lateralis. —  Origin.,  anterior  surface  of  apex  of  trans, 
proc.  of  atlas;  passes  nearly  straight  up  to  the  jugular  process  of 
occiput. 

The  two  oblique  muscles,  with  the  rect.  cap.  post,  maj.,  form  the  suboccipital 
triangle. 

Suboccipital  muscles  may  be  doubled.  M.  atlanto-mastoid.,  from  transverse 
process  of  atlas  to  hinder  part  of  mastoid. 

Nerves. — All  the  above  back  muscles  by  posterior  primary  branches  of 
spinal  n. 

Actions. — The  longitudinal  muscles  extend  the  back  with  a  force  of  200-400 
pounds :  some  of  the  lower  muscles  may  depress  the  ribs  and  aid  in  forced 
expiration ;  some  of  the  upper,  if  fixed  above,  may  act  in  forced  inspiration. 
The  muscles  of  one  side  produce  lateral  flexion  of  the  spinal  column.  The 
complexus  and  transverso-spinalis  rotate  the  head  and  spine  to  the  opposite  side. 
The  rectus  minor  and  superior  oblique  chiefly  extend  the  head ;  the  rectus  major 
and  inferior  oblique  rotate  the  atlas  and  skull  on  the  axis  ;  the  major  also  ex- 
tends the  head.  The  lev.  costarum  have  but  little  action  on  the  ribs ;  are  re- 
garded as  muscles  of  forced  inspiration.  The  rectus  lat.  bends  the  head  to  one 
side. 


MUSCLES  AND  PASCIiE  OP  THE  ABDOMEN. 

Describe  the  abdominal  muscles  and  fascise. 

The  superficial  fascia  of  the  abdomen  has  two  layers:  (1)  subcuta- 
neous^ containing  fat ;  (2)  creeper  contains  yellow  elastic  tissue,  correspond- 
ing to  tunica  abdominalis  of  animals  for  support  of  viscera.  From  the 
deeper  layer  is  derived  the  suspensoi^  ligament  of  th& penis ;  its  lower 
part,  fascia  of  Scarpa,  passes  over  Poupart's  ligament  and  ends  just  be- 
low in  the  fascia  lata.  Both  layers  pass  over  the  spermatic  cord  to  the 
scrotum,  become  reddish  and  muscular,  forming  the  dartos.  There  is 
no  deep  fascia. 

The  abdominal  muscles  fill  the  space  between  the  chest,  lumbar  ver- 
tebrae, and  pelvis. 

(a)  Vertical  MuscJes. — 1.  M.  rectus  abdominis,  separated  from  its  fel- 
low by  the  Hnea  alba. — Origin.,  cartilages  of  fifth,  sixth,  and  seventh 
ribs,  and  usually  bone  of  fifth,  by  three  slips,  sometimes  from  the  ensi- 
form ;  insertion,  by  two  tendons,  the  inner  smaller  one  into  the  front  of 
the  symphysis  pubis,  crossing  its  fellow  of  the  opposite  side,  passing  down 
and  out  to  adductor  fascia,  down  and  in  to  fascia  of  penis ;  the  outer  head 
into  the  pubic  crest  or  space  in  front  of  it  if  the  pyramidalis  is  lacking. 
(Henle  considers  the  insertion  as  below,  as  it  passes  into  so  much  mov- 
able fascia. )  The  fibres  are  interrupted  by  zigzag  tendinous  inscriptions, 
the  three  naost  constant  being  one  at  the  umbilicus,  one  at  the  lower  end 
of  the  ensiform,^  and  one  between  these  two :  if  one  or  two  more  are 
added,  they  are  incomplete  and  below  the  umbilicus.  They  do  not  pen- 
etrate the  whole  thickness  of  the  muscle ;  may  extend  into  the  internal 
10— A, 


146  MUSCLES   OF  THE   TRUNK. 

oblique ;  are  not  vestiges  of  ribs,  but  of  the  septa  between  the  original 
vertebral  myotomes. 

Jf.  rectus  lateralis  ahd.,  1  inch  (2.5  cm.)  broad,  between  the  external  and 
internal  oblique  muscles,  from  the  tenth  rib  down  over  the  eleventh  to  the 
middle  of  the  iliac  crest. 

2.  M.  pyramidalis  rests  on  lower  part  of  rectus  inside  its  sheath, 
separated  from  it  by  a  special  fascia.  Origin^  front  of  pubis  below  in- 
sertion of  outer  tendon  of  rectus,  passes  over  the  lower  third  of  the 
space  between  the  umbilicus  and  pubis ;  inserted  into  the  linea  alba.  Its 
inner  fibres  are  vertical,  outer  ones  oblique. 

The  height  of  the  muscle  is  variable,  unlike  on  both  sides,  one  lacking ; 
both  lacking  in  every  fourth  case ;  doubled  on  one  or  both  sides.  When  lack- 
ing the  lower  part  of  the  rectus  is  increased  in  size. 

The  linea  alba  is  a  fibrous  structure  from  the  ensiform  to  the  pubis, 
formed  by  the  union  of  the  oblique  and  transverse  aponeuroses,  broadest 
above,  \  inch  (4-7  mm.),  and  a  little  below  its  middle  is  the  cicatrix  of 
the  umbilicus.  At  the  lower  end  it  passes  in  front  of  the  recti,  and  here 
is  detached  posteriorly  a  band  of  longitudinal  ^xq^=:  adiminicidiim 
lineoe  albce^  spreading  out  triangularly  behind  the  outer  heads  of  the 
recti.  The  linea  semilunaris  is  a^  narrow  part  of  the  internal  oblique 
aponeurosis  just  before  it  divides  into  two  layers.  Linece  transvei^sce 
correspond  to  the  intersections  of  the  rectus. 

(6)  Transverse  Muscles. — 1.  M.  obliguus  externus^  or  descending  oblique, 
muscular  on  the  side,  aponeurotic  in  front. — Origin.,  outer  surfaces  and 
lower  borders  of  the  lower  eight  ribs  (seven,  Henle)  by  slips  in  a  serrated 
series,  five  interdigitating  with  the  serratus  magnus,  the  lower  three  with 
the  lat.  dorsi,  from  lumbo-dorsal  aponeurosis  connected  with  first  lumb. 
vert.  The  slip  from  the  eighth  rib  is  broadest,  the  others  diminish 
above  and  below  that ;  upper  and  lower  digitations  rise  from  near  the 
costal  cartilages,  the  intermediate  ones  at  some  distance  from  them. 

The  fibres  from  the  last  two  ribs  pass  nearly  vertically  down  to  the 
anterior  half  of  the  outer  lip  of  the  iliac  crest ;  all  the  rest  incline  down 
and  forward  to  the  aponeurosis.  This  is  wider  below  than  above,  meets 
its  fellow  in  the  linea  alba,  is  connected  with  the  costo-xiphoid  ligament, 
gives  origin  to  the  lowest  fibres  of  the  pect.  major,  or  is  covered  by  a 
fascia  derived  from  it ;  below  it  extends  from  the  anterior  superior  spine 
of  the  ilium  to  the  spine  of  the  pubis  as  a  thickened  border  called 
Poupart.s  ligament. 

The  aponeurosis  is  perforated  by  a  large  opening  near  the  pubis  for 
the  spermatic  cord  in  the  male  and  round  ligament  in  the  female :  this 
is  the  external  abdominal  ring  (annulus  inguinalis  cutaneus,  p.  7i.).  It 
is  oval  or  elliptical,  1  inch  long,  J  inch  wide  in  the  male,  with  its  base  at 
the  pubic  crest;  its  sides  are  the  pillars  (crus  superius  and  crus  inferius, 
p.  71.) ;  the  U2^per  or  inner  is  flat  and  straight,  attached  to  the  anterior 
surface  of  the  pubis,  decussating  with  its  fellow  or  passing  to  adductor 


MUSCLES   AND    FASCIA   OF   THE   ABDOMEN.  147 

fascia  and  dorsum  of  penis ;  the  lower  or  external  is  thin  above,  and 
below  is  formed  by  the  inner  end  of  Poupart's  Hg.,  attached  to  the  spine 
of  the  pubis. 

The  deepest  fibres  of  Poupart's  Hg.  are  sent  back  to  the  inner  part  of 
the  ilio-pectineal  line  for  f  inch,  forming  a  layer  called  Gimhernat's  liga- 
ment^ presenting  upper  and  lower  surfaces  and  a  concave  margin  toward 
the  femoral  ring  and  vein.  Some  of  the  fibres  of  Gimbernat's  lig.  or  of 
the  outer  pillar  are  reflected  up  and  in,  under  the  spermatic  cord,  behind 
the  inner  pillar,  in  front  of  the  conjoined  tendon,  covering  the  posterior 
wall  of  the  external  ring,  and  pass  to  the  sheath  of  the  rectus  and  linea 
alba  or  interlace  with  its  opposite :  this  is  the  reflected  Gimhernaf  s  liga- 
ment or  triangular  ligament  of  Colles. 

Transverse  fibres  bind  together  the  oblique  fibres  of  the  aponeurosis, 
and  where  they  cross  the  ring  they  are  called  inter  columnar  fibres.  From 
them  a  thin  membrane  is  prolonged  upon  the  spermatic  cord,  known  as 
the  intercolumnar  or  spermatic  fascia.       • 

Generally  the  ext.  oblique  and  lat.  dorsi  leave  a  triangular  space  be- 
tween them  on  the  iliac  crest,  forming  Petit' s  triangle,  where  thirty  or 
forty  cases  of  lumbar  hernia  have  been  recorded. 

The  external  inguinal  ligament  of  Henle  (lig.  inguinale  ext.)  is  a 
strengthening  band  of  fascia  along  the  outer  part  of  Poupart's  Hg.  It 
springs  from  the  anterior  superior  spine  by  two  flat  roots  which  form  a 
short  canal  for  the  external  cutaneous  nerve :  it  runs  transversely,  and  is 
fused  with  the  iliac  fascia  at  the  lower  edge  of  the  ext.  obi.  aponeurosis 
as  far  as  the  crural  arch  ;  there  it  passes  over  the  femoral  vessels  and  is 
lost.  It  receives  fibres  from  the  ext.  obi.  aponeurosis,  and  sends  fibres 
down  to  the  fascia  lata  over  the  sartorius,  so  that  a  sagittal  section  of  the 
ligament  and  connected  fasciae  is  in  the  form  of  a  St.  Andrew's  cross. 
The  superficial  fascia,  and  with  it  the  skin,  are  attached  to  the  lig.  ing. 
ext.,  and  form  the  inguinal  sulcus  (fold  of  groin).  Internally  this  liga- 
ment gives  ofl'  the  intercolumnar  fibres,  and  may  end  in  them  or  in  the 
ext.  obi.  apon.  or  in  the  lig.  ing.  int. 

2.  M.  Obliquus  Internum. — Origin,  outer  half  of  Poupart's  lig.,  ante- 
rior two-thirds  of  middle  ridge  of  iliac  crest,  from  lumbar  fascia ;  inser- 
tion, lower  margins  of  cartilages  of  last  three  ribs,  its  aponeurosis,  and 
by  conjoined  tendon  (with  transversalis)  arching  over  the  inguinal  canal 
to  the  front  of  the  pubis  and  inner  part  of  ilio-pect.  line  behind  Gim- 
bernat's lig.  The  aponeurosis  splits  at  the  outer  border  of  the  rectus ; 
the  anterior  layer  unites  with  the  ext.  obi.  apon.,  the  posterior  with  the 
transversalis  apon.,  which  reunite  and  form  the  sheath  of  the  rectus; 
the  posterior  layer  is  attached  above  to  the  ensiform,  seventh  and  eighth 
rib-cartilages.  This  division  of  aponeurosis  stops  a  little  above  halfway 
between  the  umbilicus  and  pubis,  and  below  this  point  the  int.  obi.  apon. 
and  transversalis  apon.  pass  wholly  in  front  of  the  rectus.  This  de- 
ficiency in  the  posterior  wall  of  the  sheath  is  marked  by  a  lunated  edge, 
concave  downward,  the  semilunar  fold  of  Douglas  (linea  Douglasii, 
p,  71. ) ;  here  the  rectus  is  separated  from  the  abdominal  contents  by 


148  MUSCLES   OF   THE  TRUNK. 

peritoneum,  subperitoneal  tissue,  transversalis  fascia,  and  a  thin  con- 
nective tissue  which  continues  the  trans,  apon.  (Note  a  difference 
between  trans,  fascia  and  apon.) 

Int.  obi.  muscle  may  present  a  fibrous  inscription  or  cartilaginous  slip  op- 
posite the  tenth  or  eleventh  rib ;  fold  of  Douglas  is  often  indistinct,  may  be 
lacking. 

The  cremaster  muscle,  peculiar  to  the  male,  is  attached  externally  to 
the  inner  portion  of  Poupart's  lig.,  and  is  continuous  with  the  int.  obi. 
fibres :  its  internal  attachment  (inconstant)  is  the  spine  and  crest  of  the 
pubis ;  it  descends  in  folds  in  front  of  the  spermatic  cord  to  the  level  of 
the  testis,  and  spreads  out  in  a  cremasteric  fascia.  Some  regard  this 
muscle  as  a  part  of  a  foetal  structure  called  guhernaculum  testis.  There 
are  some  remains  of  it  in  the  female. 

3.  M.  Transversalis  Abdominis. — Origin^  inner  surface  of  the  lower 
six  rib-cartilages,  interdigitating  with  the  diaphragm,  from  lumbar  trans, 
proc.  by  a  posterior  aponeurosis,  from  anterior  three-fourths  of  inner  mar- 
gin of  iliac  crest,  outer  third  of  Poupart's  lig.  This  muscle  nearly  sur- 
rounds the  abdomen,  and  is  inserted  into  the  anterior  aponeurosis  and 
conjoined  tendon.  This  apon.  commences  for  the  most  part  about  1  inch 
from  the  outer  border  of  the  rectus  in  the  linea  Spigelii  (p.  n.),  but 
muscular  fibres  nearly  meet  behind  the  rectus  above  :  the  lower  third  of 
this  apon.  passes  in  front  of  the  rectus. 

The  posterior  aponeurosis  is  the  middle  layer  of  the  lumbar  fascia  or 
lumbo-costal  lig.  (Henle),  between  the  erector  spinae  and  quad.  lumb. 
muscles.  The  highest  part  of  this  muscle  is  continuous  with  the  triang. 
sterni. 

Muscle  may  be  absent ;  m.  puho  transversalis  behind  conjoined  tendon  from 
ilio-pectineal  line  to  trans,  fascia  or  aponeurosis. 

Nerves. — Supplied  in  general  by  lower  intercostal  n. ;  int.  obi.  and  trans- 
versalis also  by  ilio-hypogastric  and  ilio-inguinal  n. ;  cremaster  by  genital 
branch  of  genito-crural  n. 

Actions. — Upon  thorax,  viscera,  or  vertebral  column  ;  pelvis  and  thorax  fixed, 
they  aid  vomiting,  expulsion  of  foetus,  fseces,  and  urine;  vertebral  col.  fixed,  they 
raise  diaphragm  by  pressing  up  viscera,  and  so  aid  expiration;  flex  thorax  to 
front  or  laterally,  or  rotate  it  if  vert.  col.  be  not  fixed ;  thorax  fixed,  draw  up 
pelvis  in  climbing.    Pyramidales  make  linea  alba  tense. 

LINING  FASCIiE  OF  THE   ABDOMEN. 

The  transversalis  fascia  covers  the  inner  surface  of  that  muscle,  and 
is  continued  upon  the  under  surface  of  the  diaphragm  :  along  the  inner 
margin  of  the  iliac  crest  it  is  attached  to  periosteum  ;  for  about  2  inches 
internal  to  the  ant.  sup.  iliac  spine  it  is  attached  to  the  back  of  Poupart's 
lig.  and  iliac  fascia  ;  next  internally  it  passes  down  over  the  femoral  ves- 
sels as  the  anterior  portion  of  their  sheath  :  as  it  passes  under  Poupart's 
lig.  it  is  strengthened  by  the  deep  crural  arch  (arcus  cruralis),  a  band  of 
fibres  inserted  into  the  pubic  spine  and  ilio-pectineal  line  behind  the  con- 


LINING   FASCIA  OF   THE   ABDOMEN.  149 

joined  tendon :  it  includes  beneath  it,  between  the  femoral  vein  and 
Gimbernat's  lig.,  the  femoral  ring,  through  which  a  femoral  hernia  may 
descend. 

Halfway  between  the  ant.  sup.  iliac  spine  and  symphysis  pubis  is  the 
internal  abdominal  ring  (annulus  inguinalis  abdominalis,  p.  n. ) :  its  lower 
edge  is  vertically  J  inch  (8  mm.)  above  Poupart's  lig.  and  IJ  inches  (4 
to  5  cm. )  from  the  outer  ring. 

From  the  inner  end  of  the  ilio-pectineal  line  fibres  of  transversalis 
fascia  go  in  two  directions — outward,  beneath  the  internal  ring  and 
parallel  with  Poupart's  lig.,  the  lig.  inguinale  int.  laterale;  upward,  on 
the  inner  side  of  the  ring  as  the  lig.  ing.  int.  mediale  (outer  and  inner 
parts  of  internal  inguinal  ligament).  These  two  form  a  blunt  angle, 
limiting  the  internal  ring  below  and  internally.  From  the  margin  of 
the  ring  is  prolonged  the  delicate  infundihuliform  fascia  (processus 
vaginalis  fasciae  trans. )  The  ring  is  the  entrance  into  this  process,  the 
lower  sharp  border  of  which  is  the  plica  semilunaris  fascice  trans,  (fre- 
quently lacking). 

In  the  region  of  the  umbilicus  are  strengthening  fibres  covering  the 
obliterated  umbilical  vein  ^=  fascia  transversalis  umhilicalis. 

The  iliac  fascia  covers  the  ilio-psoas  muscle,  stretched  from  the  iliac 
crest  to  the  ihac  portion  of  the  ilio-pect.  line :  it  is  continued  up  on  the 
psoas,  attached  to  the  sacrum,  in  vertebral  disks,  internal  arched  ligament 
of  diaphragm,  and  externally  to  ilio-lumbar  ligament  (ant.  layer  of  lumbar 
fascia).  Below  it  passes  beneath  the  femoral  vessels,  forming  the  hinder 
part  of  the  femoral  sheath :  outside  the  vessels  it  unites  with  the  trans- 
versalis fascia  on  Poupart's  ligament  and  with  the  ext.  ing.  Hg.,  which 
prolongs  it  to  the  fascia  lata  (ihac  portion) ;  internally  it  joins  the  pubic 
portion  of  the  fascia  lata.  A  strong  band  is  att,ached  to  the  ilio-pect. 
eminence  between  the  psoas  and  pectineus,  called  the  ilio-pect.  lig. 

Describe  the  fasciae  of  the  perineum  and  pelvis. 

Fasdce  of  Perineum,  Superficial. — In  the  anterior  half  of  the  peri- 
neum, continuous  with  the  dartos,  is  the  superficial  perineal  fascia,  or 
fascia  of  Colics,  bound  to  the  ischio-pubic  rami  as  far  back  as  the  ischial 
tuberosities :  on  a  line  from  this  tuberosity  to  the  central  point  of  the 
perineum  it  turns  round  the  transversus  perinei  muscle  and  becomes 
deep  perineal  fascia.  There  is  an  incomplete  median  septum,  so  that 
extravasated  urine  distends  one  side  of  the  scrotum  beneath  the  dartos, 
then  penetrates  to  the  other  side,  then  to  the  front  of  the  abdomen  be- 
neath the  superficial  fascia,  but  does  not  pass  to  the  posterior  half  of  the 
perineum  nor  down  upon  the  thighs.  BucFs  fascia  is  the  continuation 
forward  of  Colles'  fascia,  investing  the  penis  as  far  as  the  glans,  contin- 
uous with  the  dartos,  and  directing  the  urine  as  already  stated. 

The  deep  perineal  or  subpubic  fascia  or  triangular  ligament  of  the 
urethra  is  stretched  across  the  subpubic  arch  on  the  deep  surface  of  the 
crura  and  bulb,  and  consists  of  two  layers :  the  inferior  layer  extends 
back  to  the  central  point  of  the  perineum,  attached  to  the  ischio-pubic 


150  MUSCLES   OF  THE  TRUNK. 

rami,  connected  at  its  base  with  the  other  layer,  and  continuous  with  the 
recurved  margin  of  the  superficial  perineal  fascia.  The  transverse  lig. 
of  the  pelvis  is  connected  with  this  layer,  and  meeting  from  below  the 
arcuate  pubic  lig.  (subpubic)  forms  an  aperture  for  the  dorsal  vein  of  the 
penis.  This  layer  is  perforated  by  the  urethra,  arteries  of  the  bulb  and 
of  the  corpora  cavernosa.  Between  the  two  layers  of  the  triangular 
ligament  are  the  membranous  portion  of  the  urethra,  the  constrictor 
urethrae,  Cowper's  glands,  pudic  vessels,  and  dorsal  nerves  of  penis. 

T\iQ  superior  (deep)  layer  consists  of  right  and  left  lateral  halves,  sepa- 
rated in  the  middle  line  by  the  urethra  close  to  the  prostate,  and  con- 
tinuous on  each  side  with  the  fascia  covering  the  obt.  int.  muscle.  The 
levator  ani  is  between  this  layer  and  the  recto-vesical  fascia. 

FasdoR  of  the  Pelvis. — This  consists  of  two  parts,  obturator  and  recto- 
vesical fascia. 

The  obturator  fascia  covers  the  inner  surface  of  the  obturator  internus 
muscle ;  it  is  attached  to  the  iliac  portion  of  the  ilio-pect.  line,  to  the 
body  of  the  pubis,  to  the  great  sacro-sciatic  notch  and  great  sacro-sci- 
atic  ligament,  and  upper  edge  of  obturator  membrane ;  below  it  joins 
the  falciform  process  of  the  great  sacro-sciatic  ligament  and  bounds  the 
ischio-rectal  fossa  externally.  Near  its  upper  margin  it  gives  off  the 
anal  fa^cia^  which  covers  the  lev.  ani  externally  and  bounds  the  ischio- 
rectal fossa  internally. 

The  fascia  of  the  pyriformis  is  continued  back  from  the  obturator  in 
front  of  the  pyriformis  muscle  and  sacral  plexus. 

The  recto-vesical  fascia  is  attached  in  front  to  the  back  of  the  pubis, 
and  laterally  separates  from  the  obturator  fascia  along  a  curved  line  from 
the  upper  part  of  the  obturator  foramen  to  the  ischial  spine :  this  is  the 
posterior  part  of  the.  white  line  which  extends  from  the  pubis  to  the 
ischial  spine.  This  fascia,  covering  the  upper  surface  of  the  lev.  ani 
muscle,  passes  to  the  prostate  gland,  bladder,  rectum,  and  from  side  to 
side  across  the  median  line.  The  part  to  the  prostate  and  neck  of  blad- 
der from  the  pubis  consists  largely  of  involuntary  muscular  fibres,  the 
anterior  true  ligaments  of  the  bladder^  or  pubo-prostatic  ligaments;  out- 
side them  are  the  lateral  true  ligaments^  and  the  part  going  to  the  rec- 
tum is  the  lig.  of  the  rectum.  The  anterior  part  of  the  fascia  meets  the 
bladder  along  its  junction  with  the  prostate,  and  divides  into  two  layers : 
the  upper  (ascending)  unites  with  the  muscular  coat  of  the  bladder,  and 
is  attached  just  outside  the  vesiculse  seminales ;  the  inferior  layer  (de- 
scending) forms  the  sheath  of  the  prostate,  and  at  its  apex  is  continued 
into  the  upper  layer  of  the  triangular  ligament ;  it  also  passes  between 
the  bladder  and  rectum  and  forms  the  front  of  the  sheath  of  the  latter. 
The  vagina  receives  the  recto-vesical  fascia  in  a  manner  similar  to  the 
prostate. 

Describe  the  muscles  of  the  perineum. 

Two  groups— anal  and  genito-urinary,  with  a  superficial  and  deep  set 
in  each. 


MUSCLES   OF   THE   PERINEUM.  151 

A.  In  the  Male. — (a)  Anal  Muscles, — ^The  internal  or  circular  sphinc- 
ter is  a  thick  ring  of  unstriped  muscle  continuous  with  the  circular  fibres 
of  the  rectum. 

The  external  sphincter^  1  inch  in  depth,  is  elliptical,  attached  by  a 
small  tendon  to  tlie  coccyx,  encloses  the  anus,  and  superficial  fibres  end 
in  skin ;  some  decussate  across  the  median  line ;  a  few  deep  ones  are 
continuous  from  side  to  side,  but  a  large  part  blend  with  the  muscles 
at  the  ' '  central  point. ' ' 

The  cmtral  point  of  the  perineum  is  the  median  part  of  a  tendinous 
septum  in  which  several  muscles  meet :  it  is  1  inch  in  front  of  the  anus, 
behind  the  bulb  of  the  urethra ;  may  be  absent. 

The  levator  ani  rises  from  the  pubic  body,  adherent  to  and  between 
the  obt.  and  recto-vesical  fasciae,  from  the  "white  line,"  spine  of  the 
ischium,  and  upper  layer  of  triangular  ligament.  The  hinder  fibres  pass 
down  and  in  to  the  coccyx.  The  foremost  run  almost  directly  back  to 
the  "central  point,"  the  intervening  ones  to  the  lower  end  of  the  rec- 
tum and  median  aponeurosis  between  coccyx  and  anus,  common  to  the 
two  muscles. 

This  muscle  is  divided  by  a  cleft  just  below  the  obturator  canal  into  two 
parts:  the  anterior  pubo-coccygeus  (Savage)  is  alone  connected  with  the  rec- 
tum ;  its  outer  fibres  pass  over  the  side  of  the  prostate,  continue  the  ext. 
sphincter  upward,  unite  with  its  fellow  behind  the  bowel,  and  are  inserted 
into  the  coccyx;  the  inner  fibres  pass  between  the  two  sphincters  and  join 
the  longitudinal  fibres  of  the  rectum  and  decussate  in  front  of  the  anus.  The 
hinder  part  of  the  muscle,  iscMo-coccygeus  (Henle),  passes  from  the  pelvic 
fascia  and  ischial  spine  to  the  margin  of  the  coccyx  and  median  aponeurosis. 

The  coccygeus,  or  levator  coccygeus^  rises  by  its  apex  from  the  ischial 
spine  and  obturator  fascia,  and  is  inserted  by  its  base  into  the  margin  of 
the  coccyx  and  lower  part  of  the  sacrum.  This  with  the  above  muscle, 
on  both  sides,  constitute  the  pelvic  diaphragm, 

M.  sacrO'Coccygeus  anticus,  curvator  coccygis,  from  anterior  surface  of  sacrum 
to  anterior  surface  of  coccyx. 

(h)  Genito-iirinai^  Muscles. — Three  on  each  side  and  a  central  deep 
one. 

Transversus  Perind. — Origin.,  ischial  tuberosity  passes  forward  and 
inward  to  unite  with  its  fellow,  the  external  sphincter,  and  bulbo-cavern- 
osus  at  the  "central  point." 

Very  variable,  inconstant  insertion,  absent,  composed  of  several  slips.  M. 
gluteo-perinealis  from  glut.  max.  to  this  muscle. 

Ischio-cavernosu,%  or  Erector  Penis. — Origin^  inner  part  of  tuberosity 
and  ramus  of  ischium,  behind  and  on  each  side  of  the  attachment  of 
crus  penis :  its  tendon  spreads  over  the  crus,  and  is  inserted  into  the 
outer  and  under  sides  of  that  body  at  its  fore  part. 


152  MUSCLES   OF  THE  TRUNK. 

Houston  describes  the  m.  compressor'  vense  dorsalis  penis,  rising  in  front  of  the 
crus  and  erector  penis,  and  joining  its  fellow  above  dorsal  vein ;  it  is  well  de- 
veloped in  the  dog. 

Bulbo-cavernosus,  or  ejacidator  urhice.^  unites  with  its  fellow  in  a  median 
raphe  continued  forward  from  the  ' '  central  point, ' '  the  two  covering  the 
bulb  and  part  of  the  corpus  spongiosum.  Its  fibres  ascend  from  the 
raphe  and  end  on  the  dorsum  of  the  corpus  spong.  by  joining  its  fellow ; 
at  the  fore  part  some  pass  to  the  outer  side  of  the  corpus  cavernosum 
and  send  an  expansion  over  -the  dorsal  vessels ;  some  of  the  posterior 
fibres  unite  with  the  under  surface  of  the  triangular  ligament. 

The  fibres  surrounding  the  bulb  are  somewhat  distinct  from  the  rest,  and 
have  been  described  as  the  m.  compressor  hemispliserum  bulbi. 

The  above  three  muscles  and  enclosed  triangular  space  are  between 
the  superficial  and  deep  perineal  fasciae — i.  e.  below  the  lower  layer  of 
the  triangular  ligament. 

The  constrictor  or  compressor  urefhroe  rises  from  the  ischio-pubic  rami, 
from  the  two  layers  of  the  triangular  ligament,  between  which  it  is 
placed,  and  surrounds  the  membranous  portion  of  the  urethra,  forming 
a  kind  of  sphincter.  A  median  raphe  sometimes  divides  the  muscle.  Its 
hindermost  fibres  have  been  described  as  the  trans,  permei  profundus. 

Most  of  the  fibres  pass  transversely,  others  obliquely,  others  circularly 
around  the  urethra,  and  on  the  inferior  surface  is  a  longitudinal  slip  from  the 
base  to  the  apex  of  the  triangular  ligament. 

Nerves. — External  sphincter  by  fourth  sacral  and  inf.  hemorrhoidal  of 
pudic ;  lev.  ani  by  fourth  sacral  and  perineal  branch  of  pudic ;  coccygeus  by 
fourth  sacral ;  the  three  superficial  gen. -urinary  muscles  by  the  perineal 
branch  of  the  pudic ;   constrictor  urethrse  by  dorsal  nerve  of  penis. 

Actions. — Int.  sphincter  wholly  involuntary,  external  usually  involuntary, 
but  made  firmer  by  act  of  will ;  lev.  ani  and  coccygeus  support  and  raise  floor 
of  pelvis,  and  thus  have  to  do  with  forced  expiration  ;  the  levator  also  assists 
in  emptying  the  lower  rectum,  raising  and  expanding  its  "aperture,  but  some 
of  its  fibres  act  with  the  ext.  sphincter  in  closing  the  anus ;  the  transversi  fix 
the  "central  point "  and  give  support  to  the  ejaculator  muscles  ;  the  ischio- 
cavernosi  compress  the  crus  and  help  produce  and  maintain  the  erection  of 
the  penis ;  the  bulbo-cavernosi  forcibly  eject  fluid  mostly  voluntarily  at  the  end 
of  micturition,  involuntarily  in  the  emission  of  semen ;  they  also  are  supposed 
to  aid  erection  of  penis ;  the  constrictor  urethrx  assists  the  bulbo-cavernosi  in 
clearing  the  urethra  and  erects  penis  (Henle). 

B.  In  the  female^  the  transversus  perinei^  ext.  sphincter.,  lev.  ani.,  erec- 
tor clitoridis  (ischio-cavernosus)  correspond  to  similar  muscles  of  the 
male,  the  sphincter  vagince  to  the  bulbo-cavernosi.  The  constrictor  ure- 
thrce  is  the  trans,  perinei  profundus,  and  differs  from  that  of  the  male 
by  being  divided  into  lateral  halves  by  the  vagina. 

Describe  the  diaphragm  or  midriff. 

A  partition  between  the  abdomen  and  thorax,  rising  by  muscular  fibres 
as  vertebral^  costal^  and  sternal  portions. 


THE   DIAPHRAGM.  153 

The  crura^  or  pillars  of  the  vertebral  portion,  connected  with  the  ant. 
common  lig. ,  rise  from  the  bodies  and  intervertebral  subs,  of  the  lumbar 
vertebrae,  the  right  from  the  second,  third,  and  fourth,  the  left  from  the 
second  and  third  ;  they  arch  over  the  aorta  from  right  to  left,  and  meet 
behind  it  from  left  to  right.  The  muscular  fibres  from  them  form  a 
figure  8,  leaving  an  opening  for  the  oesophagus.  The  internal  arched 
ligament  passes  over  the  psoas  muscle  from  the  outer  side  of  the  first 
lumbar  body  to  the  second  trans,  proc.  The  external  arched  ligament 
passes  over  the  quad,  lumborum  from  the  second  trans,  proc.  to  the 
last  rib ;  they  are  the  upper  margins  of  fascia  covering  those  muscles  ; 
an  arched  ligament  may  pass  over  both  muscles ;  muscular  fibres  of 
the  diaphragm  rise  from  both. 

The  costal  portion  rises  from  the  lower  six  cartilages,  interdigitating 
with  the  transversalis  abd.  The  sternal  portion  is  very  short — a  single 
muscular  slip,  sometimes  two,  from  the  ensiform  cartilage. 
,  The  central  tendon^  trefoil,  forms  the  highest  part,  convex  in  front, 
concave  behind ;  has  three  lobes,  the  right  being  the  largest,  the  left  the 
smallest ;  the  tendinous  fibres  are  interwoven  in  every  direction. 

There  are  three  foramina. :  the  hiatus  aorticns,  in  front  of  the  first 
lumbar,  transmitting  the  aorta,  thoracic  duct,  and  yena  azygos  mag. ;  the 
foramen  for  the  oesophagus^  opposite  tenth  dorsal  vert.,  entirely  sur- 
rounded by  muscle,  oval,  transmits  oesophagus,  pneumogastric  nerves, 
and  branches  of  the  coronary  artery ;  the  foramen  quadratum  for  vena 
cava  is  in  the  highest  part  of  the  central  tendon,  at  level  of  disk  between 
the  eighth  and  ninth  dorsal  vert.  ;  its  sides  are  firmly  attached  to  the 
vein.     A  sterno-diaphragmatic  hgament  passes  to  this  foramen. 

Small  foramina  are  in  the  crura  for  splanchnics  on  both  sides,  for 
small  azygos  vein  on  left  side :  the  sympathetic  cord  perforates  the  crus 
or  passes  under  the  internal  arched  ligament. 

There  are  four  weak  places  .*  ( 1 )  between  costal  and  vertebral  portions 
near  quad.  lumb. ;  (2)  between  costal  and  sternal  portions  =  Larrey's 
spaces;  (3)  oesophageal  opening;  (4)  where  sympathetic  cords  pierce 
crura.  Left  side,  as  a  whole,  is  the  weaker:  at  Larrey's  space  is  peri- 
toneum below,  then  areolar  tissue,  then  pericardium  on  left  side  and 
pleura  on  right  side. 

Highest  point  of  diaphragm  on  right  side  in  dead  body  is  level  of 
fifth  rib-cartilage  with  sternum;  on  left  side  of  sixth  cartilage  with 
sternum  (Quain) ;  mid-portion  is  flat,  supports  the  heart,  and  is  nearly 
immovable.  A  considerable  extent  of  origin  of  diaphragm  is  in  contact 
with  the  thoracic  wall. 

Relations  are,  above,  pleurse  and  pericardium,  lungs,  and  heart;  below, 
peritoneum,  liver,  stomach,  pancreas,  spleen,  and  kidneys. 

Nerves. — Phrenics,  lower  intercostals,  and  sympathetic. 

Actions. — By  its  contraction  and  descent  the  viscera  are  pushed  down  and 
thorax  lengthened ;  it  elevates  the  ribs  when  its  vault  is  supported  by  the 
abdominal  viscera :  its  anterior  fibres  oppose  forward  movement  of  the 
sternum. 


154  MUSCLES   OF   THE  TRUNK. 

MUSCLES  AND   FASCIA   OF   THE  BREAST. 
Describe  the  breast  muscles  and  fasciae. 

IJascia  of  Pectoral  Region. — Superficial  contains  the  mammary  gland, 
sending  septa  into  it  and  supporting  it.  The  deep  fascia  is  thin :  a  part 
of  it  is  the  costo-coracoid  membrane  behind  the  pect.  major ;  this  en- 
sheathes  the  subclavius,  and  its  posterior  layer  blends  with  the  sheath 
of  the  axillary  vessels.  The  anterior  layer  from  the  coracoid  to  the  first 
rib  may  be  called  the  costo-coracoid  ligament :  it  is  prolonged  down,  in- 
vests the  pect.  minor,  and  merges  into  the  axillary  fascia  at  the  border 
of  the  pect.  major.^  The  axillary  fascia  stretches  between  the  two  folds 
of  the  axilla,  and  is  continuous  with  the  sheath  of  the  vessels  and  apo- 
neurosis of  arm. 

a.  Superficial  Breast-muscles. 

These  muscles  converge  to  their  insertion  into  the  upper  extremity 
and  its  girdle :  the  deep  ones  belong  to  the  bones  of  the  trunk,  and  are 
in  three  layers  like  the  transverse  ones  of  the  abdominal  wall. 

First  Layer. — M.  pectoralis  major,  two  portions,  clavicular  and 
sterno-costal ;  the  clavicular  portion  rises  from  the  inner  half  of  the 
anterior  surface  of  the  clavicle  and  sterno-clavicular  capsule,  the  sterno- 
costal from  the  sternum  (superficial  part,  Henle),  and  upper  six  rib- 
cartilages  (deep  part,  Henle)  and  from  anterior  sheath  of  rectus  and 
ext.  obi.  apon.  The  fibres  converge  to  be  inserted  by  two  tendons,  united 
along  the  lower  margin,  into  the  external  bicipital  ridge :  the  clavicular 
and  upper  sterno-costal  parts  form  one  tendon  with  straight  fibres :  the 
lower  sterno-costal  part  twists  so  that  its  lowest  fibres  are  inserted  highest 
up ;  a  bursa  separates  this  from  the  other  anterior  tendon.  This  poste- 
rior layer  also  gives  ofi"  three  expansions — one  over  the  biceps  tendon  to 
the  capsule  of  the  shoulder-joint,  one  lining  the  bicipital  groove,  and  one 
to  the  fascia  of  the  arm. 

Variable  in  extent  of  origin  and  separation  of  heads.  M.  chondro-epitro- 
chlearis,  from  one  or  two  rib-cartilages  below  pect.  maj.,  or  from  it  or  from 
ext.  obi.  apon.  to  fascia  of  arm,  internal  intermuscular  septum,  or  inner  epi- 
condyle.  M.  sternalis  brutorum  lies  on  pect.  maj.  parallel  to  sternum;  passes 
from  sheath  of  rectus  or  third  to  seventh  cartilages  to  sterno-mastoid,  to 
upper  cartilages,  to  sternum  or  pect.  maj.  If  two  are  present,  they  may 
unite  across  the  manubrium. 

Second  Layer. — L  M.  subclavius  rises  from  the  groove  on  the  under 
surface  of  the  clavicle  and  recess  between  the  conoid  and  trapezoid  liga- 
ments ;  inserted  into  junction  of  first  rib  with  its  cartilage  between  fibres 
of  costo-clavicular  ligament. 

May  be  attached  to  coracoid,  and  not  to  clavicle,  or  to  both,  or  to  scapula,  as 
m.  sterno-scapularis  ;  m.  sterno-claviciilaris  anticus  from  manubrium :  if  both  are 
present,  a  digastric  interclavicular  muscle  may  connect  them  across  the  manu- 
brium. Another  variety  of  this  is  m.  supraclavicular  is,  from  upper  edge  of 
manubrium,  either  anteriorly  or  posteriorly,  behind  sterno-mastoid  to  upper 


MUSCLES  AND    FASCIA   OF   THE   BREAST.  155 

surface  of  clavicle  (1  in  20).  There  may  be  the  scapulo-clavicularis  or  coraco- 
clavicularis. 

2.  M.  pectorah's  minor  from  three  ribs  near  their  cartilages,  usually 
third,  fourth,  and  fifth,  often  second,  third,  and  fourth  or  fifth,  and  from 
intercostal  aponeuroses;  insertion^  inner  border  and  upper  surface  of 
coracoid ;  a  bursa  is  under  its  insertion  (1  in  40  cases). 

Each  costal  origin  may  remain  separate  in  the  muscle :  its  insertion  may  be 
continued  into  the  capsule  and  great  tuberosity ;  the  insertion  is  represented 
normally  by  the  coraco-humeral  ligament.  Absence  of  whole  muscle.  M. 
pectoralis  minimus  (rare),  from  first  costal  cartilage  to  coracoid. 

Third  Layer. — M.  serratus  anticus^  p.  n.  (serratus  magnus),  placed 
between  ribs  and  scapula.  Origin^  first  eight  or  nine  ribs  by  as  many 
slips :  the  first  slip  is  attached  to  two  ribs ;  insertion.,  posterior  border 
of  scapula  and  into  the  flat  surfaces  at  upper  and  lower  angles,  not  in 
the  subscapular  fossa.  There  are  three  sets  of  fibres:  (1)  first  digita- 
tion,  from  first  and  second  ribs,  passes  up  to  flat  area  at  upper  angle ; 
(2)  second  and  third  digitations,  from  second  and  third  ribs,  pass  down 
in  a  thin  triangular  layer  to  the  whole  line  between  the  upper  and  lower 
angles;  (3)  the  remaining  five  or  six  digitations  converge,  some  up  and 
some  down,  to  the  flat  surface  in  front  of  the  lower  angle. 

Varieties. — Slip  from  tenth  rib ;  lower  digitations  or  slip  from  first  rib  ab- 
sent ;  may  be  united  with  levator  scapulae,  as  is  the  case  in  many  mammals. 
May  be  a  bursa  at  the  upper  angle  of  scapula  or  between  the  serratus  and 
chest- wall. 

Nerves. — The  pectoralis  major  by  the  two  anterior  thoracics ;  the  minor  by 
the  int.  ant.  thoracic  n. ;  the  subclavius  by  the  fifth  and  sixth  cervical ;  ser- 
ratus anticus  by  the  posterior  thoracic,  upper  division  by  fifth  c,  middle  by 
sixth  c.  (often  fifth  c.  also),  lower  by  sixth  and  seventh  c. 

Actions. — Pect.  major. 

Arm  at  Side,  Arm  Abducted  to  90°.  Arm  Raised  High. 

First   part  of  muscle  Draws  arm   forward  Draws    arm    forward    to 

draws  arm  up  and  and  rotates  in.  horizontal,  and  no  far- 

in.  ther. 

Second  part  of  muscle  Draws  arm  down,  in,  Adducts,  draws  down. 

draws  arm  down  and  and  rotates  in. 

rotates  in. 

It  assists  the  lat.  dorsi  in  adduction,  opposes  it  in  flexion;  lowest  fibres  are 
best  adductors ;  succeeding  ones  draw  forward ;  used  in  swimming.  Fixed 
above  the  pectorales,  draw  body  forward;  the  major  does  not  draw  up  the 
ribs,  the  minor  does  not  seem  to,  so  that  they  have  no  inspiratory  action. 

The  subclavius  depresses  clavicle  or  steadies  it ;  may  act  in  inspiration ;  sup- 
ports sterno-clavicular  joint.  The  pect.  minor  draw-s  coracoid  down  and  for- 
ward, depresses  shoulder,  throws  lower  angle  of  scapula  backward,  acts  with 
levator  and  rhomboidei  in  rotating  scapula.  The  scapula  is  slung  by  the  ser- 
ratus magnus  and  rljomboidei,  is  kept  in  equilibrium  by  them  ;  lower  portion 
of  serratus,  combined  with  trapezius,  rotates  scapula  on  an  axis  near  its  supe- 


156  MUSCLES   OF   THE   TRUNK. 

rior  angle  and  elevates  shoulder;  upper  fibres  bring  scapula  forward  and 
down,  assisted  by  pect.  minor ;  whole  muscle  brings  scapula  forward,  acts  in 
all  movements  of  pushing,  keeps  scapula  pressed  to  ribs ;  of  no  importance  in 
respiration ;  middle  fibres  only  might  pull  ribs  down. 

h.  Deep  Breast-muscles. 

First  Layer. — Mm.  intercostales  externi,  thicker  behind  than  in 
front,  are  directed  obliquely  downward  and  forward  between  the  borders 
of  two  ribs :  they  extend  from  the  tuberosities  to  the  outer  ends  of  the 
cartilages,  not  quite  reaching  them  above,  but  continued  along  their  bor- 
ders in  the  lower  two  spaces.  They  are  continued  to  the  sternum  as 
anterior  intercostal  aponeuroses  or  ligg.  intercostalia  ext. 

M.  supracostalis  from  anterior  end  of  first  rib,  from  cervical  fascia  or  scaleni 
to  fourth  or  to  second  and  third  ribs. 

Second  Layer. — Mm.  inteixostdles  interni,  thicker  in  front,  incline 
down  and  back,  but  less  obliquely  than  the  external  set ;  are  attached  to 
the  inner  surfaces  of  two  ribs.  Anteriorly  they  reach  the  sternum,  and 
the  last  two  are  continuous  with  the  int.  obi.  muscle ;  posteriorly  they 

fo  to  the  angles  or  a  little  beyond.  Their  deficiency  behind  is  supplied 
y  the  post,  mtercost  apon.^  which  merge  on  one  side  into  the  ant. 
cost,  -trans,  lig. ,  and  on  the  other  into  a  thin  fascia  between  the  muscles. 
Third  Layer. — Mtu.  Transversi  Thoracis. — 1.  M.  trans,  thoracis 
posterior  (subcostal  muscles)  are  small  slips  on  inner  aspect  of  thorax, 
connected  with  int.  intercostals  near  angles  of  ribs ;  run  in  same  direc- 
tion as  int.  intercost. ,  and  extend  over  one  or  two  spaces ;  origins^  reach 
from  twelfth  rib  to  third  ;  insertions^  from  tenth  to  second. 

2.  M.  Transversus  Thoracis  Ant.  (triangularis  sterni). — Muscular  and 
tendinous  fibres  behind  the  costal  cartilages  rise  from  ensiform,  lower 
part  of  sternum,  and  cart,  of  lower  two  or  three  true  ribs ;  fibres  pass 
up  and  out ;  lowest  are  horizontal,  middle  oblique,  and  upper  ones  nearly 
vertical ;  inserted  to  inner  surfaces  and  lower  borders  of  sixth  to  second 
costal  cartilages,  inclusive.  It  is  a  continuation  upward  of  the  trans, 
abd.  muscle ;  may  be  lacking  on  one  or  both  sides. 

Nerves. — All  by  intercostal  n. 

Actions. — Costal  and  diaphragmatic  respiration  are  normally  combined ;  the 
thorax  is  increased  antero-posteriorly  by  a  forward  movement  of  the  sternum, 
transversely  by  elevation  and  eversion  of  ribs,  vertically  by  descent  of  dia- 
phragm ;  extension  of  the  vertebral  column  is  also  an  agent.  There  are  three 
views  as  to  action  of  the  intercostals :  Hamberger's,  that  the  external  elevate 
and  internal  depress  the  ribs ;  Hutchinson's,  that  the  external  and  anterior 
parts  of  the  internal  elevate,  and  the  rest  of  the  internal  depress  ribs ;  Hal- 
ler's  is  best — that  (1)  ribs  are  not  joined  as  by  a  pivot  to  vertebral  col.;  (2) 
are  not  parallel  bars,  but  convex  arches ;  (3)  no  two  ribs  can  move  as  they 
please,  being  connected  above  and  below,  but  all  move  as  a  system :  if  fixed 
point  be  above,  both  external  and  internal  intercostals  elevate  the  ribs  and 
are  inspiratory  muscles ;  fixed  below,  they  both  depress  and  assist  expiration. 


MUSCLES   AND    FASCIA   OF   THE   NECK. 


157 


Inspiration. 


Typical  Forces. 
Elasticity  of  thorax. 
Diaphragm. 
Scaleni. 
Intercostals. 


Accessory  Forces. 
Sterno-mastoid. 
Subclavius. 

Muscles  of  back  of  neck. 
Serratus  post.  sup. 
Levatores  costarum. 


Expiration. 


Typical  Forces. 
Elasticity  of  thorax. 
Elasticity  of  lungs. 
Weight  of  thorax  and  shoulder  girdle. 
Weight  of  abdomen. 
Intercostals. 


Accessory  Forces. 
Quadratus  lumborum. 
Triangularis  sterni. 
Serratus  post.  inf. 
Abdominal  muscles. 
Levator  ani  and  coccygeus. 


MUSCLES  AND  PASCIiE  OF  THE  NECK. 
Describe  the  neck-muscles. 

Mostly  vertical,  a  superficial  or  anterior  group,  some  resembling  the 
recti  abd. ,  a  deep  or  posterior  group  corresponding  to  the  intercostals 
and  serratus  anticus. 

Anterior  Neck-muscles. 

Long  Muscles. — 1.  Platysma  myoides  (M.  subcutaneus  colli)  is  a  pale, 
thin  muscular  sheet  over  the  front  and  side  of  the  neck  and  lower  part 
of  face.  Origin.,  skin  and  subcutaneous  tissue  over  deltoid,  pectoral 
and  trapezius  muscles  in  a  line  from  anterior  end  of  second  rib  to  acro- 
mion ;  fibres  pass  up  and  in  over  clavicle,  and  are  inserted  into  the  lower 
jaw :  the  two  muscles  meet  at  the  hyoid,  and  the  right  overlaps  the  left 
one ;  the  posterior  fibres  blend  with  the  depressor  anguli  and  orbicularis 
muscles  and  fasciae.  The  muscle  does  not  rise  from  bo'ne ;  inserted  into 
bone,  muscle,  and  fascia. 

A  slip  to  this  muscle  from  the  mastoid  or  occiput ;  the  m.  occipitalis  minor 
from  the  fascia  over  the  upper  end  of  the  trapezius  transversely  to  the  fascia 
over  the  insertion  of  the  sterno-mastoid  (8  out  of  25  cases).  Platysma  repre- 
sents the  panniculus  carnosus  of  mammals,  a  skin  muscle. 

Nerves. — Inframaxillary  branch  of  facial,  but  as  this  unites  with  the  super- 
ficial cerv.  n.,  it  may  get  some  spinal  innervation. 

Action. — Draws  angle  of  mouth  down  and  out ;  may  depress  lower  jaw ;  being 
curved,  it  tends  to  redress  itself,  carries  skin  of  neck  forward,  and  is  said  to 
be  useful  in  singing  by  removing  pressure  from  great  vessels ;  used  in  swal- 
lowing and  expressing  sudden  terror ;  some  say  propels  saliva  from  parotid.  - 

Describe  the  deep  cervical  fascia  (anteriorly). 

It  passes  from  the  trapezius  muscle  beneath  the  platysma  over  the 
posterior  triangle  of  the  neck,  invests  the  sterno-mastoid,  and  passes 
over  the  anterior  triangle  to  the  median  line.  It  is  attached  below  to 
the  clavicle,  and  perforated  by  the  ext.  jugular  vein ;  attached  above  to 


158  MUSCLES   OF   THE   TRUNK. 

the  lower  jaw,  and  becomes  the  parotid  fascia  and  stylo-maxillary  lig. 
In  front  it  is  attached  to  the  hyoid  bone,  and  splits  below  the  thjToid 
gland :  the  anterior  layer  goes  to  the  anterior  surface  of  the  sternum, 
and  the  posterior,  covering  the  sterno-hj^oid  and  thyroid  muscles,  is  at- 
tached to  the  interclavicular  lig.  ;  between  these  two  layers  is  the  supra- 
sternal space,  extending  a  short  distance  on  either  side  behind  the  sterno- 
mastoid  as  the  supraclavicular  recess.  Prolonged  from  the  deeper  layer, 
a  fascia  invests  the  posterior  belly  of  the  omo-hyoid  and  holds  it  down  to 
the  first  rib,  there  connected  with  the  costo-coracoid  membrane.  A  pro- 
cess also  passes  behind  the  depressors  of  the  hyoid,  invests  the  thyroid 
body,  passes  to  the  trachea,  forms  the  carotid  sheath,  and  extends  to  the 
pericardium.  Deepest  of  all  is  i\iQ  prevertebral  fascia.  Inside  the  phar- 
yngeal muscles  is  the  pharyngeal  aj^oneurosis,  outside  them  their  proper 
fascial  layer  (bucco-pharyngeal),  connected  to  the  prevert.  fascia  by  areo- 
lar tissue,  forming  the  retro-pJiaryngeal  space.  A  prolongation  of  the 
prevertebral  fascia  forms  the  axillary  sheath. 

Regions  of  Neck. — Suprah3^oid,  submaxillary,  submental,  infrahyoid, 
fossa  suprasternalis ;  on  either  side  the  larynx  are  sulci  carotidei,  sterno- 
mastoid  region,  fossa  supraclavicular  is  minor,  above  sternal  end  of  clav- 
icle, fossa  supracl.  major,  between  trapezius  and  sterno-mastoid. 

2.  M.  Sterno-cleido-mastoideus  (its  full  name  should  mention  its  inser- 
tion into  the  occipital  bone). — Origin.,  sternal  head,  thick  and  round, 
from  anterior  surface  of  manubrium  ;  clavicular ,  from  inner  third  upper 
surface  of  clavicle.  The  two  portions  meet,  pass  up  and  back  to  the 
anterior  border  and  outer  surface  of  mastoid  and  outer  half  or  more  of 
the  superior  curved  line  of  the  occiput,  to  meet  the  trapezius.  Spinal 
access,  nerve  pierces  the  under  surface  of  the  external  portion. 

Sterno-mastoid  and  cleido-mastoid  parts  may  remain  separate ;  the  latter 
will  be  pierced  by  the  sp.  access,  nerve.  A  third  factor  may  be  added,  cleido- 
occipital,  origin  and  insertion  outside  the  cleido-mastoid.  In  animals  without 
a  clavicle  the  cleido-mastoid  part  is  continued  into  the  great  pectoral  or 
deltoid. 

M.  supraclavicularis  propritis  is  attached  to  the  clavicle  at  each  end,  forming 
an  arch  above  the  middle  of  the  bone. 

M.  levator  claviculas,  a  misplaced  part  of  the  sterno-mastoid  or  scalenus, 
springs  from  the  middle  of  the  clavicle,  and  is  inserted  into  the  fifth  and  fourth, 
fourth  and  third,  or  third  and  second  cervical  trans,  proc. 

Connected  with  the  insertion  of  the  sterno-mastoid  is  the  M.  Trans- 
versus  Nuchce.  (18  out  of  25  cases).  It  is  covered  by  the  insertion  of  the 
trapezius,  lies  below  the  superior  curved  line,  concave  above,  rises  from 
the  inner  part  of  this  line  and  ext.  occip.  protuberance,  and  is  inserted 
into  this  line  externally  and  into  the  sterno-mastoid  aponeurosis.  When 
absent  it  is  represented  by  tendinous  fibres.  Its  purpose  seems  to  be  to 
prolong  the  sterno-mastoid  insertion  backward. 

Nerves.— Both  by  spinal  accessory,  offsets  of  which  are  joined  by  the  second 
cervical. 


MUSCLES   AND   FASCIJE   OF   THE   NECK.  159 

Actions. — The  two  stern o-mastoids  draw  the  head  and  neck  forward  toward 
the  sternum  ;  one,  acting  slightly,  flexes  the  head  (extends,  Henle)  and  flexes 
laterally  and  rotates,  so  that  the  face  looks  up  and  toward  the  opposite  side. 
Fixed  above,  the  muscles  elevate  thorax  in  forced  inspiration. 

3.  Digastric  muscle  (m.  biventer  mandibulae)  has  two  bellies  united 
by  a  rounded  tendon :  the  posterior  belly  rises  from  the  digastric  fossa 
of  the  temporal  bone,  passes  down,  in,  and  forward  toward  the  hyoid 
bone.  The  anterior  belly  is  attached  close  to  the  symphysis  of  the  lower 
jaw  and  directed  down,  back,  and  slightly  outward :  the  intervening 
tendon  is  attached  to  the  body  and  great  cornu  of  the  hyoid  by  an 
aponeurosis  and  by  the  stjdo-hyoid  muscle,  which  is  pierced  by  the 
digastric  tendon.  The  anterior  bellies  of  the  two  muscles  are  connected 
by  a  dense  aponeurosis. 

Varieties. — Slip  from  styloid  process  to  post,  belly ;  slip  from  near  angle  of 
lower  jaw  to  ant.  belly ;  ant.  belly  may  be  split  and  some  fibres  cross  the 
median  line ;  muscle  may  be  monogastric  from  mastoid  to  middle  of  lower 
jaw;  digastric  tendon  may  be  in  front  of  or  behind  the  stylo-hyoid.  The 
mento-hyold  is  a  median  slip  (or  two  parallel  bands)  from  the  hyoid  to  the 
chin. 

Nerves. — Ant.  belly  by  mylohyoid  branch  of  inferior  dental  from  third 
division  of  fifth  nerve ;  post,  belly  by  facial. 

Actions. — Either  an  elevator  of  the  hyoid  or  depressor  of  lower  jaw,  accord- 
ing to  which  is  fixed ;  its  insertion  is  not  close  enough  to  the  hyoid  to  allow 
independent  action  of  either  belly. 

Hyoid-hone  Muscles, 

1.  Between  Base  of  Skull  and  Hyoid. — M.  Sfylo-hyoideus. — 
Origin,  by  narrow  tendon  from  back  of  styloid  process  near  its  root ; 
insertion,  usually  divided  for  transmission  of  digastric  tendon,  and  the 
two  portions  pass  ununited  to  the  hyoid  at  the  junction  of  the  great 
cornu  and  body;  almost  alwa3^s  a  slip  ends  in  the  digastric  tendon. 

May  be  wanting,  may  be  double;  inserted  into  digastric  tendon ;  fibres  con- 
tinued to  omo-,  thyro-,  or  mylo-hyoid  muscles.  M.  stylo-hyoideus  alter,  (stylo- 
chondro-hyoideus  or  stylo-hy.  prof.),  from  styloid  process  to  small  cornu,  accom- 
panying or  replacing  the  stylo-hyoid  lig. 

II.  Between  Thorax  and  Hyoid.— First  Layer. — 1.  M.  Stemo- 
hyoideus.  —  Origin,  back  of  sternum  and  sterno-clavicular  joint,  or  from 
joint  and  clavicle,  from  clavicle  only,  sometimes  from  first  costal  carti- 
lage ;  insertion,  inner  half  of  lower  border  of  hyoid  body.  Its  inner 
border  approaches  its  fellow;  are  far  apart  below. 

Transverse  intersection  at  level  of  omo-hyoid  tendon,  analogous  to  rect. 
abd. ;  muscle  may  be  doubled  or  absent.  M.  cleido-hyoideus  from  clavicle  to 
hyoid  in  front  of  sterno-hyoid. 

2.  M.  omo-hyoideus,  ribbon -shaped,  has  two  bellies  and  an  intermediate 
tendon.  Origin,  upper  border  scapula  near  notch  or  from  transverse 
ligament ;  passes  forward  under  trapezius  across  scaleni,  beneath  sterno- 


160  MUSCLES   OF  THE   TRUNK. 

mastoid,  then  vertically  to  lower  border  of  hyoid,  partly  beneath  and 
partly  in  front  of  the  sterno-hyoid  insertion.  Its  tendon  beneath  the 
sterno-mastoid  at  level  of  cricoid  cartilage  is  enclosed  in  the  deep  cer- 
vical fascia,  which  is  prolonged  down  to  the  sternum  and  first  costal 
cartilage,  while  the  fascia  investing  its  posterior  belly  descends  to  the 
clavicle. 

Varieties. — Frequent,  doubled  or  absent ;  clavicle  may  be  sole  origin  of  post, 
belly  (m.  deido-hyoideus) ;  band  of  fascia  may  take  the  place  of  its  ant.  belly ; 
the  post,  belly  may  have  an  accessory  slip  to  the  clavicle,  first  rib,  or  cervical 
fascia  (m.  coraco-cervicalis),  others  to  the  sterno-mastoid,  sixth  cerv.  trans, 
proc.  or  fascia  of  scalenus,  M.  cervico-costo-humeralis  has  been  seen,  from 
small  tuberosity  of  humerus,  inserted  by  two  tendons,  one  to  sixth  cerv. 
trans,  proc,  one  to  anterior  end  of  first  rib.  The  omo-hyoid  and  sterno-hyoid 
muscles  are  parts  of  the  same  muscular  sheet;  the  fascia  binding  down  the 
post,  belly  may  contain  striped  muscular  fibres ;  the  varieties  of  the  muscle 
come  from  the  different  degrees  of  cleavage  of  this  sheet. 

Second  Layer. — 1.  M.  sternothyreoideus  lies  behind  the  sterno- 
hyoid, and  rises  from  posterior  surface  of  manubrium  internal  to  the 
sterno-hyoid,  variably  from  first  and  second  costal  cartilages,  diverges 
from  its  fellow ;  inserted  into  oblique  line  of  thyroid  cartilage,  covering 
some  fibres  of  the  inf  constrictor. 

Muscles  united  at  origin,  absent  or  doubled;  transverse  inscriptions;  a  slip 
to  fascia  of  neck  {costo-fascialis)f  or  one  from  the  carotid  sheath  to  the  outer 
border  of  the  muscle. 

2.  M.  thyreohyoideus^  a  continuation  of  the  preceding  from  the  oblique 
line  of  the  thjToid  cartilage  to  the  outer  half  of  the  lower  border  of  the 
hyoid  and  anterior  half  of  great  cornu. 

M.  hyo-thyroideus  lat.  from  apex  of  great  cornu  to  apex  upper  horn  of  thy- 
roid cart.    M.  cricohyoideus  between  cricoid  cart,  and  hyoid  bone. 

M.  transversus  colli,  in  the  lower  part  of  the  neck,  represents  the  mm.  trans, 
abd.  and  thoracis :  it  springs  from  the  upper  edge  of  the  first  costal  cartilage, 
and  passes,  fan-shaped,  in  many  fine  tendinous  fibres  between  the  sterno- 
hyoid and  sterno-thyroid  muscles,  meeting  or  crossing  its  fellow  in  the  middle 
line:  some  fibres  end  in  the  interclavicular  ligament  or  stern o-clavicular 
capsule. 

III.  Muscles  :Setween  Lower  Jaw  and  Hyoid  Bone. 

First  Layer. — M.  Myhhyoideus. — Origin^  from  mylo-hyoid  ridge  of 
lower  jaw,  extending  from  last  molar  tooth  nearly  to  symphysis;  fibres 
pass  inward,  back,  and  downward,  hinder  ones  to  body  of  hyoid,  a  larger 
number  into  the  median  raphe  between  the  two  muscles,  which  extends 
from  near  the  symphysis  to  the  hyoid ;  the  posterior  border  is  free ;  the 
two  muscles  form  the  "  diaphragm  of  the  mouth." 

May  be  closely  connected  with  or  replaced  by  ant.  belly  of  digastric ;  may 
receive  slip  from  other  hyoid  muscles ;  may  be  deficient  at  fore  part. 

Second  Layer. — 31.  gemohyoideus  has  a  narrow  origin  from  the 


MUSCLES   AND   FASCIA   OF   THE   NECK.  161 

inf.  mental  spine ;  fibres  pass  straight  back  to  anterior  surface  of  body 
of  hyoid,  and  frequently  send  a  small  slip  to  the  small  cornu  over  the 
hyoglossus  or  another  to  the  great  cornu.  It  may  be  blended  with  its 
fellow  or  doubled. 

iVieri;es.— Stylo-hyoid  by  facial,  mylo-hyoid  by  mylo-byoid  branch  of  inf. 
dental  of  third  div.  of  fifth;  all  the  others  of  this  group  attached  to  the 
hyoid  bone  apparently  by  the  hypoglossal,  but  really  by  the  first,  second,  and 
third  cerv.  nerves  via  the  conimunicans  and  descendens  noni  (so  called). 

Actions. — Sterno-hyoid  and  omo-hyoid  depress  the  hyoid  bone ;  the  sterno-thy- 
roid  depresses  that  cartilage,  may  make  vocal  cords  tense,  but  with  the  thyro- 
hyoid depresses  the  hyoid  bone ;  the  latter  also  draws  up  the  larynx ;  may 
relax  vocal  cords,  and  produces  descent  of  epiglottis.  These  muscles  restore 
the  larynx  and  hyoid  after  the  act  of  swallowing,  and  depress  them  in  utter- 
ance of  low  tones.    The  infrahyoid  muscles  may  act  in  forced  inspiration. 

The  mylo-hyoid  and  genio-Jiyoid  elevate  the  hyoid  and  draw  it  forward,  or 
depress  the  lower  jaw,  depending  upon  which  is  fixed :  the  former  raises  the 
floor  of  the  mouth  and  forces  food  back.  The  stylo-hyoid  acts  only  on  the 
hyoid  bone ;  aided  by  the  mid.  constrictor,  it  draws  it  up  and  back. 

Describe  the  extrinsic  muscles  of  the  tongue. 

M.  genio-hyoglossus^  fan-shaped,  is  placed  vertically  in  contact  with 
its  fellow.  Origin,  superior  mental  tubercle ;  lower  fibres  .pass  to  body 
of  hyoid  and  side  of  pharynx,  superior  to  tip  of  tongue,  and  intermediate 
to  whole  length  of  tongue,  vsome  decussating  across  the  median  line. 

Slips  may  pass  to  the  epiglottis,  stylo-hyoid  lig.,  or  small  cornu  of  hyoid 
bone. 

M.  hyoglossus  is  flat  and  quadrate.  Origin,  whole  length  of  great 
cornu  and  lateral  part  of  hyoid  body ;  insertion,  posterior  half  of  tongue, 
where  fibres  spread  forward  and  inward  over  the  dorsum,  joining  the 
styloglossus.  The  fibres  from  the  hyoid  body  may  be  called  the  hasio- 
glossus,  those  from  the  great  cornu  the  keratoglossus. 

The  triticeo-glossus  rises  from  the  cartilago  triticea  in  the  thyro-hyoid  lig., 
and  enters  the  tongue  with  the  posterior  part  of  the  hyoglossus. 

The  chondroglossus  is  often  described  as  a  part  of  the  above,  but  is 
separated  from  it  by  the  pharyngeal  fibres  of  the  genio-hyoglossus.  Ori- 
gin, inner  side  of  base  of  small  cornu  and  from  part  of  hyoid  body ;  its 
fibres  end  on  the  dorsum  of  the  tongue  near  the  middle  line. 

M.  Styloglossus. — Origin,  front  of  styloid  process  near  apex,  and 
largely  from  stylo-maxillary  lig.  ;  insertion,  side  and  under  part  of  tongue 
as  far  as  tip,  decussating  and  blending  with  the  hyoglossus  and  palato- 
glossus. 

The  lingualis  is  the  intrinsic  tongue-muscle,  presenting  inferior,  supe- 
rior, transverse,  and  vertical  fibres,  with  a  median  fibrous  septum. 

M.  myloglossiis  is  an  accessory  slip  of  the  styloglossus  from  angle  of  jaw 
or  stylo-max.  lig.  to  the  tongue.  M.  stylo-auricularis,  from  cartilage  of  exter- 
nal auditory  meatus  to  styloid  process  or  styloglossus  muscle :  a  fibrous  band 
is  often  found  here. 

11— A. 


162  MUSCLES   OF   THE   TRUNK. 

Nerves. — Motor  supply  by  hypoglossal. 

Actions — Genio-hyoglossus,  hinder  part  protrudes  the  tongue,  front  part  re- 
tracts, middle  part  or  nearly  whole  muscle  depresses  and  makes  dorsum  con- 
cave ;  in  hemiplegia  the  sound  fibres  push  apex  over  to  paralyzed  side.  The 
hyoglossus  and  chondroglossus  retract,  depress,  and  make  dorsum  convex ;  the 
styloglossus  draws  tongue  back,  elevates  the  base,  and  makes  dorsum  concave. 

Describe  the  muscles  of  the  pharynx. 

There  are  two  layers :  an  outer,  called  constrictors,  three  in  number, 
with  a  transverse  direction ;  an  inner,  called  elevators,  two  in  number, 
with  a  longitudinal  direction. 

Inferior  Constrictor  (laryngo-pHaryngeus). — Origin,  cricoid  cart,  at 
lower  and  back  part,  inf.  cornu,  oblique  line  and  upper  tubercle  of  the 
thyroid  cart.  ;  some  fibres  continue  into  it  from  sterno-thyroid  and  crico- 
thjToid  muscles.  It  unites  with  its  fellow  in  the  median  line ;  its  inferior 
fibres  are  horizontal,  and  a  few  enter  the  longitudinal  layer  of  the 
oesophagus,  and  highest  end  on  a  raphe  about  1  inch  below  the  basilar 
process.  Superficial  fibres  of  one  side  become  deep  in  the  other,  or  may 
join  the  fibres  of  another  constrictor.  This  covers  the  middle  con- 
strictor ;  the  sup.  laryngeal  nerve  and  vessels  enter  the  larynx  above  its 
upper  border,  and  the  inferior  nerve  and  vessels  beneath  its  lower  border. 

Middle  Constrictor  (hyo-pharyngeus). —  Origin,  large  and  small  cornua 
of  hyoid,  from  stylo-hyoid  lig.  ;  fibres  diverge  greatly,  covering  nearly 
the  whole  length  of  the  pharynx,  and  meet  behind  in  the  median  line : 
the  lowest  are  beneath  the  inf  constrictor,  the  highest  overlap  the  sup. 
constrictor,  the  intermediate  ones  are  transverse.  The  stjdo-pharyngeus 
muscle  separates  this  from  the  sup.  constrictor. 

Fibres  may  come  from  the  hyoid  body,  tongue,  or  mylo-hyoid  ridge ;  a  fre- 
quent slip  from  the  lateral  thyro-hyoid  lig.  is  the  m.  syndesmo-pharyngeus. 

Superior  Constrictor  (cephalo-pharyngeus). — Origin,  side  of  tongue, 
mucous  membrane  of  mouth,  alveolus  at  end  of  mylo-hyoid  ridge,  pterygo- 
max.  lig.,  hamular  process,  and  lower  third  of  internal  pterygoid  plate: 
the  fibres  curve  back  and  blend  with  the  opposite  muscle  or  end  in  the 
aponeurosis  which  fixes  the  pharynx  to  the  basilar  process.  Of  all  the 
constrictors,  only  the  upper  half  of  this  muscle  ends  in  a  raphe  (linea 
alba).  The  upper  margin  curves  round  the  lev.  palati  and  Eustachian 
tube ;  the  space  intervening,  closed  by  fibrous  membrane,  is  the  sinus  of 
Morgagni. 

These  muscles  are  covered  externally  by  dense  connective  tissue,  which 
is  prolonged  forward  to  the  pterygo-max.  lig. ,  and  is  continuous  with  the 
membrane  over  the  buccinator  muscle ;  hence  it  is  called  the  bucco- 
pharyngeal fascia.  Next  comes  the  muscular  layers,  next  the  pharyn- 
geal apon.,  and  next  the  mucous  membrane.^ 

The  m.  stylo-pharyngeus  rises  from  the  inner  surface  of  the  styloid 
process  near  the  root,  passes  down  and  in  under  cover  of  the  middle 
constrictor,  joined  by  the  palato-pharyngeus,  and  ends  on  the  superior  and 
posterior  borders  of  the  thyroid  cart,  and  lateral  wall  of  the  pharynx. 


PLATE  XL 

Fig.  I.— To  face -page  161. 


Muscles  of  the  Tongue,  left  side. 

Fig.  %— To  face  page  170. 

Rectus  superior. 

Levator  \ 

qmlpebrce  superior. 

Obliquus  superior. 


Its  upper  head. 

Lower  head. 
Rectus  inferior. 

The  Relative  Position  and  Attachment  of  the  Muscles  of  the  Left  Eyeball. 


PLATE  XII. 

Fig.  1 . — To  face  page  163, 


'  p  h  a'i 
Muscles  of  the  Soft  Palate,  the  pharynx  being  laid  open  from  behind. 


MUSCLES   AND  FASCIA   OF   THE   NECK.  163 

The  m.  palato-pharyngeus  will  be  described  with  the  palatal  muscles. 

Varieties. — Splitting  or  doubling  or  a  division  into  three  parts ;  supernu- 
merary elevators  are  common,  passing  to  constrictors  or  fibrous  wall  of  phar- 
ynx ;  from  petrous  portion  or  vaginal  process  =  petro-pharyngeus,  from  spine  of 
S]^henoid  =  spheno-pharyngeiis,  fTom  hamular  process  =  pterygo-pharynyeus  ext., 
from  basilar  itrocess  =  occipito-pharyvgeus,  from  mastoid  process  (rare)  =^7iar- 
yngo-mastoideus  ;  a  small  slip  to  raphe  from  pharyngeal  spine  =?  azygos-pharyngis. 

Nerves. — ^Pharyngeal  plexus  and  motor  fibres  from  bulbar  part  of  sp.  access, 
n.,  glosso-pharyngeal  also  for  mid.  constrictor ;  inf.  constrictor  has  in  addition 
fibres  from  ext.  and  inf.  laryngeal  nerve.  Stylo-pharyngeus  is  supplied  by 
gl  osso-phar  y  n  geal . 

Describe  the  muscles  of  the  soft  palate. 

The  soft  palate  (velum  pendulum  palati)  is  continued  back  from  the 
hard  palate,  pendulous  posteriorly,  prolonged  in  the  middle  into  the 
uvula^  and  laterally  into  the  posterior  pillars  of  the  fauces^  which  run  to 
the  side  of  the  pharynx:  another  fold  in  front  is  the  anterior  pillar  of 
the  fauces^  descending  to  the  tongue ;  between  them  is  the  tonsil,  and  the 
constricted  part  between  the  anterior  pillars  is  the  isthmus  of  the  fauces. 
There  are  five  pairs  of  muscles — two  superior,  one  intermediate,  and  two 
inferior. 

The  palato-glossus  (constrictor  isthmi  faucium,  glosso-staphylinus)  occu- 
pies the  anterior  pillar  of  the  fauces :  at  its  origin  it  is  below  all  the 
other  palatal  muscles,  and  continuous  with  its  fellow ;  inferiorly  it  enters 
the  side  of  the  tongue  and  joins  the  transverse  fibres. 

M.  amygdalo-glossus  normally  ascends  from  the  side  of  the  tongue  to  the 
tonsil. 

The  palato-pharyngeus  (pharyngo-staph3dinus)  rises  by  two  layers 
which  embrace  the  lev.  palati  and  azygos  uvulae :  the  superficial  (pos- 
terior) layer  is  thin,  the  deep  (anterior)  laj^er  is  stronger,  meets  its 
fellow,  and  rises  in  part  from  the  hard  palate  and  apon.  of  the  velum  ; 
it  receives  one  or  two  fibres  from  the  cartilage  of  the  Eustachian  tube 
(salpingo-pharyngeus).  It  passes  down  in  the  posterior  pillar,  mingling 
with  the  stylo-pharyngeus,  is  inserted  into  the  upper  and  hinder  borders 
of  the  thyroid  cartilage  and  fibrous  laj^er  of  pharynx,  passing  to  or  cross- 
ing the  median  line. 

The  azygos  wpw?oe  (palato-staphylinus),  supposed  to  be  single,  consists 
of  two  slips  which  rise  from  the  soft  palate  and  posterior  nasal  spine  and 
descend  into  the  uvula,  separated  above,  united  below. 

Levator  Palati  (petro-staphylinus). —  Origin^  petrous  portion  of  tem- 
poral bone  in  front  of  carotid  canal,  from  lower  margin  of  cartilage  of 
Eustachian  tube,  passes  forward  over  the  sup.  constrictor,  and  is  inserted 
by  its  fore  part  into  the  apon.  of  the  palate,  and  posteriorly  it  meets  its 
fellow  under  cover  of  the  azygos  uvulae. 

Circumflexus,  or  Tensor  Pa/a^i  (spheno-staphylinus). —  Origin^  scaphoid 
fossa  at  root  of  int.  pterygoid  plate,  spine  of  sphenoid,  and  outer  side  of 
Eustachian  tube ;  descends  vertically  inside  the  int.  pterygoid  muscle ; 


164  MUSCLES   OF   THE   TRUNK. 

its  tendon  turns  round  the  hamular  process,  where  there  is  a  bursa,  then 
passes  horizontally  to  its  insertion  into  the  transverse  ridge  of  the 
palate  bone  and  apon.  of  soft  palate. 

From  before  backward  in  the  soft  palate  is  the  palato-glossus,  tensor 
palati,  ant.  part  of  palato-pharyngeus,  levator  palati,  azj^gos  uvulae,  post, 
part  of  palato-pharyngeus,  and  mucous  membrane. 

iVerves.— Sources  not  fully  determined :  tensor  palati  through  otic  ganglion 
from  third  division  of  fifth ;  lev.  palati,  azygos  uvulse,  palato-glossus,  and 
palato-pharyngeus  probably  by  bulbar  portion  of  sp.  access,  nerve  through 
pharyngeal  plexus. 

Actions. — The  constrictors  are  nearly  immovable  behind,  and  so  carry  back 
the  anterior  wall,  the  hyoid  bone  and  larynx  being  carried  up  and  back  by 
the  obliquity  of  the  two  lower  constrictors.  The  upper  part  of  the  sup.  con- 
strictor cannot  act  directly  upon  the  food,  as  it  is  attached  at  both  ends  to 
immovable  parts.  The  stylo-pharyngeiis  is  the  chief  elevator  of  the  pharynx 
and  larynx ;  the  palato-glossi  depress  the  soft  palate,  elevate  the  tongue,  and 
shut  off  the  mouth-cavity  from  the  pharynx;  the  palato-pharyngei  depress  the 
soft  palate,  raise  the  pharynx,  and  bring  the  post,  pillars  together;  the  azygos 
uvulse  raises  and  shortens  the  uvula :  the  lev.  palati  raises  the  palate ;  the  tensor 
palati  tightens  and  supports  the  palate  against  the  pull  of  other  muscles  and 
opens  the  Eustachian  tube  in  deglutition.  Some  hold  that  the  tube  is  closed 
in  deglutition  by  the  lev.  palati  pressing  its  floor  against  its  upper  and  outer 
wall.  The  first  stage  of  deglutition  is  effected  by  the  mylo-hyoid,  stylo-glossus, 
and  palato-glossus  pressing  the  tongue  against  the  palate ;  the  hyoid  is  also 
raised  by  its  elevators ;  the  larynx  is  then  carried  up  beneath  the  hyoid  by  the 
thyro-hyoid  and  stylo-pharyngeus,  root  of  tongue  is  drawn  back  by  the  stylo- 
glossi and  epiglottis  pressed  down ;  at  the  same  time  the  soft  palate  is  raised 
and  fixed  by  its  proper  muscles ;  the  post,  pillars  and  uvula  shut  off  the  poste- 
rior nares,  and  the  food  is  guided  into  the  lower  pharynx,  where  it  is  grasped 
by  the  constrictors  in  succession  and  forced  into  the  oesophagus. 

Posterior  Neck-muscles. 

These  are  divided  by  the  trans,  proc.  into  two  groups.  The  outer 
from  the  processes  to  the  ribs  corresponding  to  the  intercostals,  those 
from  the  processes  to  the  shoulder-blade  corresponding  to  the  serratus 
magnus ;  the  inner  group  passes  from  one  process  to  another,  long  or 
short. 

Outer  group,  four  in  number. — 1.  M.  Scalenus  Anticus. — Origin, 
anterior  tubercles  of  trans,  proc.  of  third,  fourth,  fifth,  and  sixth  cerv. 
vert. ;  insertion,  by  a  thick  flat  tendon  into  the  scalene  tubercle  and  upper 
surface  of  first  rib  to  neighborhood  of  the  cartilage ;  the  pleura  is  at- 
tached to  the  lower  part  of  the  inner  surface  of  this  muscle. 

2.  M.  Scalenus  Medius. —  Origin,  tendinous  above,  muscular  below, 
from  posterior  tubercles  of  trans,  proc.  of  all  the  cerv.  vert,  (sometimes 
not  of  atlas) ;  insertion,  upper  edge  and  outer  surface  of  first  rib  from 
the  tuberosity  to  the  subclavian  groove. 

3.  M.  Scalenus  Posticus,  smaller  than  the  others.  Origin,  by  two  or 
three  tendons  from  the  posterior  tubercles  of  the  lower  two  or  three  cerv. 


MUSCLES   AND   FASCTJE   OF  THE   NECK.  165 

vert. ;  mserfion,  by  an  aponeurotic  tendon  into  the  second  rib  external 
to  the  serratus  post.  sup. 
Some  regard  the  scalenus  mass  as  one  muscle  with  three  insertions. 

Varieties. — A  slip  from  scaj^nus  ant.  may  pass  behind  the  subclavian  artery. 
Scalenus  post,  may  be  absent  or  go  to  third  rib.  Scalenus  pleuralis,  from  trans, 
proc.  of  seventh  cerv.  vert.,  spreads  out  in  fascia,  supporting  the  dome  of  pleura ; 
inserted  into  inner  border  of  first  rib. 

Scalenus  minimus  and  lateralis,  the  former  a  slip  of  the  anticus  to  the  first 
rib,  the  latter  of  the  posticus  to  the  second  rib.  M.  transversalis  cervicis 
meclius,  between  the  scalenus  medius  and  posticus,  connecting  the  second  and 
fourth  with  the  sixth  and  seventh  trans,  proc. 

4.  M.  Levator  Scapulce  (lev.  anguli  scapulae). — Origin^  by  distinct 
slips  from  the  trans,  proc.  oiP  the  upper  four  cerv.  vert,  between  the  at- 
tachments of  the  splenius  and  scaleni ;  msertwn,  posterior  border  of 
scapula  from  spine  to  superior  angle. 

Vertebral  attachments  various :  a  slip  to  it  from  the  occipital  bone  or  mas- 
toid process ;  parts  from  vertebrae  may  remain  separate  to  insertion.  In 
quadrupeds  it  unites  with  the  serratus  anticus  (magnus),  and  forms  one 
muscle ;  may  send  a  slip  to  the  scaleni,  trapezius,  serrated  muscles,  or  first 
and  second  ribs. 

I)ine7'  Group. — Long  Muscles. — 1.  M.  hngus  colli  rests  on  the  front  of 
the  vertebral  column  from  the  atlas  to  the  third  dorsal  vert.  There  are 
three  sets  of  fibres :  [a)  vertical  part ^  from  bodies  of  lower  two  cervical 
and  upper  two  or  three  dorsal ;  on  its  outer  border  it  receives  slips  from 
the  lower  three  or  four  cerv.  trans,  proc. ;  inserted  into  bodies  of  second, 
third,  and  fourth  cerv.  vert.  ;  [h)  lower  oblique  part^  from  bodies  of 
upper  two  or  three  dorsal,  into  anterior  tubercles  of  fifth  and  sixth  cerv. 
trans,  proc.  ;  (c)  upper  oblique  part  is  the  m.  longus  atlantis  of  Henle. 
Origin^  anterior  tubercles  of  trans,  proc.  of  third,  fourth,  and  fifth 
cerv.  vert.  ;  inserted  into  the  vertical  portion  and  lateral  and  lower  part 
of  anterior  tubercle  on  arch  of  atlas. 

Slip  from  lower  oblique  part  may  be  inserted  into  head  of  first  rib.  M. 
transversalis  cervicis  anticus,  from  anterior  tubercles  of  trans,  proc.  of  lower 
four  cerv.  vert,  to  the  body  of  the  axis  and  trans,  proc.  of  the  atlas. 

2.  3f.  Longus  Atlantis  (see  preceding  muscle). 

3.  M.  Longus  Capitis^  p.  n.  (rectus  capitis  anticus  major). — Origin^ 
anterior  tubercles  of  trans,  proc.  of  third,  fourth,  fifth,  and  sixth  cerv. 
vert. ;  insertion^  basilar  process  of  occipital  in  front  of  the  foramen  mag- 
num ;  it  may  show  a  tendinous  inscription  anteriorly ;  pharynx  is  closely 
attached  to  it. 

Short  Muscles. — 1.  Mm.  Intertransversarii  Anteriores. — Anterior  in- 
tertransverse muscles  pass  as  little  fasciculi  between  the  anterior  tuber- 
cles of  the  trans,  proc.  of  the  cerv.  vert.  ;  they  are  in  front  of  the  nerve- 
trunks.  The  one  for  the  axis  is  inserted  broadly  into  its  trans,  proc. 
They  may  be  lacking  for  the  two  upper  vertebrae. 

2.  M.  Rectus  Capitis  Anticus ,  p.  n.  (rect.  cap.  ant.  minor). — Origin^ 


166  MUSCLES   OF   THE  TRUNK. 

front  of  root  of  trans,  proc.  of  atlas ;  insertion^  basilar  process,  between 
foramen  magnum  and  rectus  major,  J  inch  from  its  fellow. 

Nerves. — Eectus  anticus  minor  by  first  cerv.  nerve ;  scaleni  and  long  pre- 
vertebral muscles  by  neighboring  nerves ;  the  J/evator  scapulae  by  the  third, 
fourth,  and  fifth  cerv.  nerves. 

Actions. — The  scalene  muscles  are  elevators  of  the  ribs,  muscles  of  inspira- 
tion ;  fixed  at  the  ribs  are  lateral  flexors  of  the  neck,  or  both  sides  together 
bend  it  forward ;  the  recti  antici  flex  the  head  and  throw  forward  the  phai*- 
ynx ;  the  longus  colli  flexes  the  neck,  and  its  oblique  parts  may  rotate;  the 
levator  scapulse  elevates  the  superior  angle  and  base  of  scapula,  counteracting 
the  rotation  of  the  trapezius ;  fixed  below,  draws  neck  back  and  to  one  side. 

MUSCLES   OF  THE  HEAD. 
Describe  the  head-muscles. 

These  belong  to  the  skull  and  f^ce ;  those  of  the  face  are  in  three 
groups  and  in  three  layers. 

Epicranial  Muscles. 

M.  Upicramus,  p.  n.  (occipito-fron talis),  comprises  the  occipital  and 
frontal  muscles  on  either  side,  united  by  the  Galea  aponeurotica.  p.  ii. 
(epicranial  apon.).  This  covers  the  upper  surface  of  the  skull  without 
division,  closely  attached  to  integument  and  loosely  to  pericranium. 
Behind,  it  is  attached  to  the  occipitales  muscles,  to  the  occipital  pro- 
tuberance, and  supreme  curved  lines;  anteriorly  it  terminates  in  the 
frontales ;  laterally  has  no  distinct  margin,  but  beneath  it  a  thin  fascia 
springs  from  the  superior  temporal  line  and  passes  under  the  auricular 
muscles  to  the  pinna.  The  frontalis  muscle  (m.  epicr.  frontalis)  rises 
from  the  aponeurosis  between  the  coronal  suture  and  frontal  eminence ; 
inferiorly  it  ends  in  subcutaneous  tissue  at  the  root  of  nose  (pyramidalis 
nasi  is  a  part  of  it,  Henle),  inner  canthus  of  eye,  and  whole  length  of 
eyebrow,  continued  into  the  pyramidalis  nasi  and  interlacing  with  the 
corrugator  supercilii  and  orbicularis ;  the  margins  of  the  right  and  left 
are  united  near  the  root  of  the  nose,  but  separated  higher  up. 

The  occipitalis  mu.'icle  (m.  epicr.  occip. )  is  attached  to  the  outer  two- 
thirds  of  the  superior  curved  line  and  to  the  mastoid  process :  its  fibres, 
1  to  2  inches  long,  terminate  in  tendon,  and  that  in  aponeurosis;  an 
interval  between  the  muscles  is  occupied  by  aponeurosis. 

Henle  describes  the  auricular  mmcles  as  a  part  of  the  epicranius ;  the 
m.  epicr.  temporalis  is  the  auricularis  anterior  of  Quain ;  rises  from  the 
root  of  the  zygoma  and  bony  external  auditory  meatus ;  connected  with 
the  helix  and  capsule  of  lower  jaw,  its  fibres  pass  up  and  forward  to  the 
edge  of  the  frontalis  muscle  and  orbicularis  oculi,  and  meet  the  platysma 
below. 

The  m.  {epicr.)  auricularis  superior  rises  from  the  Galea  apon.,  and 
converges  to  the  helix  by  one  tendon,  and  by  another  to  an  eminence  on 
the  inner  surface  of  the  pinna. 


MUSCLES   OF   THE    HEAD.  167 

The  m.  (epicr.)  aurimlaris posterior  rises  from  the  mastoid,  sterno-mas- 
toid  apon. ,  and  outer  part  of  superior  curved  line,  and  is  inserted  into 
the  vertical  ridge  at  the  back  of  the  concha.  All  of  the  ear-muscles  are 
more  or  less  connected. 

The  post,  auricular  muscle  may  rise  far  back  along  the  superior  curved  line. 
A  deep  anterior  auricular  muscle  may  pass  normally  from  the  zygoma  to  the 
tragus. 

Actions, — The  frontales  elevate  eyebrows,  draw  scalp  forward,  and  wrinkle 
forehead  transversely ;  occipitales  draw  scalp  back  or  may  alternate  with  the 
frontales.  Most  persons  have  only  partial  control,  best  in  case  of  frontales. 
The  actions  of  the  ear-muscles  are  slight  or  nil ;  the  anterior  makes  tense  the 
temporal  fascia,  and  has  no  effect  on  the  ear ;  they  may  enlarge  the  entrance 
to  the  external  ear. 

Muscles  of  Eyelids  and  Eyebrow, 

M,  orbicularis  oculi^  p.  n,^  has  three  parts,  is  thin  and  elliptical,  covers 
the  eyelid,  and  extends  some  distance  on  the  forehead,  temple,  and  cheek. 

The  pars  palpebral  is  J  p,  ??.,  is  contained  in  the  eyelids,  rises  from  the 
upper  and  lower  margins  of  the  int.  tarsal  lig. ,  and  passes  out  in  a  slight 
curve  to  the  ext.  tarsal  lig.  A  thicker  fasciculus  along  the  free  margin 
of  each  lid  is  the  ciliary  bundle. 

The  pars  orbitalis^  p,  n. ,  is  larger  and  stronger,  attached  to  the  nasal 
process  of  the  superior  maxilla,  inner  part  of  orbital  arch,  and  externally 
to  the  cheek,  forming  a  series  of  concentric  loops.  The  m.  malaris  of 
Henle  are  the  lower  converging  fibres  of  the  orbital  part,  passing  to  the 
skin  of  the  cheek  and  muscles  of  upper  lip. 

The  pars  laclirymalis^  p.  n.  (tensor  tarsi  or  Horner's  musde),  extends 
from  the  lachrymal  crest  behind  the  sac,  and  divides  into  two  slips  be- 
hind the  lachrymal  canals  for  the  ciliary  bundles  of  the  orbicularis. 

The  internal  palpebral  ligament  (tendo  oculi)  is  2  lines  long  and  at- 
tached to  the  nasal  process  of  the  sup.  maxilla  in  front  of  the  lachrymal 
groove ;  thence  it  passes  to  the  inner  commissure  of  the  eyelids,  spUt- 
ting  and  terminating  on  the  tarsi ;  it  crosses  the  lachrymal  sac  in  front, 
and  gives  off  a  process  which  passes  behind  the  sac  to  the  crest  of  the 
lachrymal  bone. 

The  external  palpebral  lig,  is  weaker,  and  attaches  the  lids  to  the  ma- 
lar bone. 

The  corrugator  supercilii  (described  by  Henle  as  a  part  of  the  orbic- 
ularis) rises  from  the  glabella,  and  passes  up  and  out  to  end  at  the  mid- 
dle of  the  orbital  arch  in  the  orbicularis  and  skin  of  eyebrow. 

The  levator palpebrce  sup,  will  be  described  with  the  orbital  muscles. 

Actions. — Palpebral  part  closes  the  lids ;  upper  half  of  orbital  part  depresses 
the  eyebrow  and  opposes  the  frontalis,  used  in  forcible  closure  of  lids;  in 
common  winking  the  palpebral  part  carries  forward  the  int.  palpebral  lig. 
and  anterior  wall  of  lach.  sac,  and  sucks  in  tears  ;  the  pars  lachrymalis  (ten- 
sor tarsi)  probably  alternates  with  the  palpebral  part,  draws  back  the  palpe- 
bral lig.,  and  compresses  the  sac.  The  corrugator  produces  vertical  wrinkles 
at  the  inner  end  of  the  eyebrow. 


168  MUSCLES   OF   THE   TRUNK. 

Muscles  of  Face. 
First  Layer. — In  muscular  individuals  this  may  be  a  continuous 
layer  under  the  skin,  converging  to  the  corners  of  the  mouth,  but  it  is 
usually  divided  into — 1.  M.  zygomaticus^frmnmsilsiY  hone  near  zygomatic 
suture  to  angle  of  mouth,  inserted  into  skin  and  mucous  membrane  by 
two  layers,  mingling  with  the  levator  and  depressor  anguli  oris. 

The  so-called  zyg.  minor  is  very  inconstant,  and  is  best  described  as  a  head 
of  another  muscle. 

2.  M.  risorms  (Santorini),  thin  fasciculi  from  masseteric'  or  parotid 
fascia  passing  over  platysma  to  skin  at  angle  of  mouth ;  is  not  a  part  of 
the  platysma. 

May  rise  from  skin  over  sterno-mastoid,  from  zygoma,  external  ear,  or  fascia 
over  mastoid ;  may  be  double  or  triple. 

^  3.  M,  triangularis  menti  (depressor  anguli  oris),  from  external  oblique 
line  of  lower  jaw  ;  fibres  converge  partly  to  skin  at  angle  of  mouth,  and 
partly  to  orbicularis  of  upper  lip ;  anterior  edge  is  concave  and  posterior 
convex. 

M.  transversus  menti,  from  inner  border  of  the  depressor  down  aud  in  below 
chin,  across  median  line  to  corresponding  point  on  other  side. 

At  the  corner  of  the  mouth  the  various  decussating  muscular  fibres  give  rise 
to  a  dense  mass  or  knot  external  to  the  lip-commissure. 

^  Second  Layer. — 1.  M.  quadratus  lahii  sup.^  p.  7i.,  lies  along  the 
side  of  nose,  from  orbit  to  upper  lip,  and  rises  by  three  heads — caput  an- 
gulare^  p.  n. ,  =  levator  labii  sup.  alaeque  nasi ;  caput  infraorhitale^  p.  n. , 
^■lev.  labii  sup.  proprius ;  and  caput  zygomaticum^  p.  tz.,  =  zygomat. 
minor.  Caput  angulare  rises  from  nasal  process  of  sup.  max.,  generally 
connected  with  the  frontalis,  and  separates  into  two  fasciculi  below — one 
to  the  skin  of  the  wing  of  the  nose,  the  other  to  the  skin  of  the  upper 
lip  or  cheek,  blending  with  the  orbicularis  oris  and  the  next  head. 

The  middle  head,  caput  infraorhitale,  rises  from  the  anterior  surface 
of  the  upper  jaw  and  its  malar  process  in  a  line  passing  from  above  the 
infraorbital  foramen  down  and  out  to  the  suture  between  the  sup.  max- 
illa and  malar  bones,  and  inserted  behind  the  caput  angulare  into  the 
skin  of  the  wing  of  the  nose  and  of  the  upper  lip. 

The  outer  head,  caput  zygomaticum  (zygomaticus  minor),  rises  from 
the  tuberosity  of  the  malar,  strengthened  by  bundles  of  the  malaris  mus- 
cle, and  passes  to  skin  of  upper  lip  and  to  the  caput  infraorbitale  (lev. 
labii  sup.). 

2.  M.  Caninus  (levator  anguli  oris). —  Origin^  canine  fossa  below  in- 
fraorbital foramen,  covered  by  the  quadratus ;  passes  down  and  out  to 
skin  at  the  angle  of  the  mouth,  and  a  large  number  of  fibres  decussate 
with  the  depressor  anguli  oris  or  are  continued  to  the  orbicularis  of  the 
lower  lip ;  it  almost  always  receives  a  slip  from  nasal  process  of  the  sup. 
maxilla  close  under  the  caput  angulare. 


MUSCLES   OF   THE   HEAD.  169 

3.  M.  Quadratm  Menti  (depressor  labii  inferioris). — Origin^  lower 
jaw  from  near  symphysis  to  beyond  the  mental  foramen ;  passes  in  to 
its  fellow,  and  inserted  into  the  skin  of  the  lower  lip  and  orbicularis ;  it 
is  really  a  continuation  of  the  platysma. 

Third  Layer. — Lateral  Muscles. — M.  huccinator  (trumpet  muscle), 
a  flat  layer  forming  a  large  part  of  the  wall  of  the  mouth  ;  attached  at 
upper  and  lower  margins  to  alveoli  of  maxillary  bones  opposite  the  molar 
teeth,  posteriorly  to  the  pterygo-maxillary  hg.,  separating  it  from  the 
superior  constrictor  of  the  pharynx ;  fibres  become  thickened  at  angle 
of  mouth  and  join  the  orbicularis ;  higher  and  lower  fibres  are  directed 
to  corresponding  lips,  middle  ones  decussate,  the  upper  to  the  lower  hp, 
the  lower  to  the  upper  lip. 

Median  Muscles. — 1.  Sphincter  oris^  or  m.  orhicidaris  oris,  is  an  ellip- 
tical sheet  making  the  foundation  of  the  lips,  composed  largely  of  trans- 
verse and  vertical  fibres  from  the  buccinator  and  elevators  and  depressors 
of  the  angle  of  the  mouth ;  there  are  also  sagittal  fibres  between  the  skin 
and  mucous  membrane.  The  deeper  fibres  and  a  distinct  marginal  band 
from  the  buccinator  pass  from  side  to  side  without  interruption  ;  the  le- 
vator and  depressor  anguli  fibres,  which  have  crossed  at  the  corner  of 
the  mouth,  enter  the  more  superficial  parts  and  are  inserted  into  the 
skin  of  the  middle  portion  of  the  lip,  mostly  after  crossing  the  median 
line  and  decussating  with  their  fellows ;  these  do  not  reach  the  free  bor- 
der of  the  Hp. 

2.  Mm.  incisivi  attach  the  orbicularis  to  bone.  The  upper  lip  has  two 
slips  on  each  side,  an  outer,  or  m.  indsivus  svp.,  from  the  incisor  fossa, 
and  an  inner,  m.  nasodabialis,  from  the  septum  of  the  nares ;  the  lower 
lip  has  one  fasciculus  on  a  side,  m.  indsivus  inf. .  from  the  incisor  fossa. 
These  all  pass  out  toward  the  corners  of  the  mouth. 

^  The  sagittal  fibres  are  more  developed  in  the  infant,  are  in  the  mar- 
ginal portion,  and  constitute  the  m.  labii  proprius. 

3.  M.  nasalis,  p.  n.,  includes  slips  usually  distinguished  as  compressor 
naris  and  depressor  alee  nasi  (outer  part).  The  former  rises  from  the  sup. 
maxilla  by  the  side  of  the  anterior  nasal  aperture,^  and  meets  its  fellow 
in  the  median  line  over  the  cartilages  of  the  nose  in  an  expansion  com- 
mon to  it  and  the  pyramidalis  nasi.  The  depressor  alee  nasi  rises  from 
the  incisor  fossa,  and  is  inserted  by  its  outer  part  into  the  back  of  the 
ala  of  the  nose,  and  by  its  inner  part  into  the  septum,  called  depressor 
septi,  p.  n. 

The  pyramiidalis  nasi  is  a  prolongation  of  the  frontalis,  decussating 
with  its  fibres,  and  attached  to  skin  at  the  lower  median  part  of  the  fore- 
head and  to  the  tendinous  expansion  of  the  compressor  naris  below. 

There  are  other  indistinct  fibres  of  nasal  muscles — the  dilator  naris 
posterior  and  anterior. 

M.  anomalus  of  Albinus  is  frequently  present  beneath  the  common  elevator 
of  lip  and  nose  (quadratus  labii  sup.),  passing  from  nasal  process  of  sup.  maxilla 
to  same  bone  below,  connected  with  comp.  naris. 


170  MUSCLES   OF   THE   TRUNK. 

4.  M.  mentalis,  p.  ??.,  levator  labii  inf.  or  lev.  menti,  from  incisor  fossa 
of  lower  jaw,  passing  down  between  depressors  of  lower  lip  to  integu- 
ment of  chin ;  it  forms  the  furrow  of  the  chin. 
^  At  the  apex  of  the  chin  between  the  periosteum  and  soft  parts  is  some- 
times a  bursa. 

M.  anomaliis  menti  usually  continues  the  above  fibres  to  the  region  of  the 
mental  foramen. 

Nerves. — All  the  muscles  of  head  and  face  above  described  (muscles  of  ex- 
pression) get  their  motor  supply  from  the  facial ;  perhaps  the  frontalis  and 
orbicularis  oculi  are  supplied  from  the  oculo-motor  nucleus,  and  not  the 
facial. 

Actions  of  the  nasal  muscles  are  indicated  by  their  names :  the  pyramidalis  nasi 
wrinkles  the  skin  at  the  root  of  the  nose  and  draws  down  that  of  the  fore- 
head ;  dilatation  of  the  alae  is  not  usually  seen  unless  in  dyspncea.  Of  the 
lip-muscles,  the  orbicularis  oris  draws  the  lips  together  vertically  and  trans- 
versely and  presses  them  against  the  teeth ;  the  zygomaticus  draws  the  angle 
of  the  mouth  up  and  back  ;  the  risorius  retracts  the  angles  of  the  mouth  ;  the 
buccinator  flattens  the  cheek,  keeps  food  between  the  teeth,  or  expels  air  from 
the  mouth :  thfi  levator  menti  draws  up  the  chin  integument,  and  so  protrudes 
the  lower  lip.  Actions  of  other  muscles  are  indicated  by  their  names ;  all 
have  to  do  with  the  expression  of  passions. 

Describe  the  muscles  of  the  orbit. 

There  are  seven  for  description.  The  m.  levator  pdlpebrce  superioris 
[origin^  above  optic  foramen  and  sup.  rectus)  ends  in  a  membranous  ex- 
pansion ;  inserted  into  the  fibrous  tarsus  of  the  upper  eyelid. 

A  thin  superficial  layer  is  continued  over  the  tarsus  to  the  skin  of  the  lid ; 
some  fibres  are  attached  to  the  conjunctiva,  to  the  wall  of  the  orbit,  and  to 
the  trochlea. 

The  four  straight  muscles  have  a  continuous  tendinous  origin  at  the 
apex  of  the  orbit  from  a  ligamentous  ring  which  encircles  the  optic 
foramen  and  crosses  the  sphenoidal  fissure ;  most  of  the  fibres  spring 
from  two  common  tendons:  the  upper  one  rises  from  the  inferior  root  of 
the  small  wing  of  the  sphenoid,  and  is  prolonged  into  the  internal,  supe- 
rior, and  external  recti;  the  lower  (Zinn)  rises  from  the  body  of  the 
sphenoid  and  divides  into  three  slips  for  the  internal,  inferior,  and  ex- 
ternal recti.  All  the  recti  are  inserted  into  the  sclerotic  3  or  4  lines  from 
the  cornea ;  the  external  has  two  heads,  between  which  pass  the  third, 
nasal  branch  of  the  fifth,  the  sixth  nerve,  and  ophthalmic  vein.  The 
external  and  inferior  recti  are  the  longest,  internal  broadest,  and  supe- 
rior smallest. 

^  The  superior  ohh'que,  or  trocJdearis,  is  internal  to  the  lev.  palpebrae, 
rises  just  in  front  of  the  optic  foramen,  and  passes  forward  to  a  round 
tendon  which  plays  through  a  fibro-cartilaginous  ring  attached  to  the 
trochlear  fossa  of  the  frontal :  it  is  there  bent  out,  back,  and  down  be- 
tween the  sup.  rectus  and  eye,  and  is  inserted  beneath  the  outer  edge 
of  the  sup.  rectus  midway  between  the  cornea  and  optic  nerve.  The 
pulley  is  lined  by  a  synovial  sheath. 


MUSCLES   OF   THE   HEAD.  171 

The  inferior  oblique  rises  from  the  orbital  plate  of  the  sup.  maxilla 
close  outside  the  orifice  of  the  nasal  duct :  the  muscle  passes  out,  back, 
and  up  between  the  inferior  rectus  and  floor  of  orbit,  and  is  inserted 
under  cover  of  the  ext.  rectus  at  the  back  part  of  the  eyeball,  nearer 
to  the  optic  nerve  than  to  the  cornea. 

Varieties. — M.  tensor  trochlex  is  a  muscular  slip  from  the  lev.  palpebrse  to 
the  trochlea  ;  the  occasional  gracilUmus  rises  with  the  sup.  oblique  and  passes 
beneath  it  to  the  trochlea ;  the  ext.  rectus  may  have  separate  heads  to  the 
insertion.  An  accessory  inf.  rectus  may  pass  from  the  inf.  rectus  to  the  inf. 
oblique ;  the  transversus  orhitse  is  an  arched  muscle  from  the  orbital  plate  of 
the  ethmoid  across  the  upper  surface  of  the  eyeball  to  the  outer  wall  of  the 
orbit. 

Nerves. — External  rectus  by  the  sixth  nerve,  sup.  oblique  by  the  fourth,  and 
the  other  five  by  the  third  nerve. 

Actions. — Lev.palpehrx  is  the  elevator  of  the  upper  lid  and  antagonist  of  the 
palpebral  part  of  the  orbicularis.  The  eyeball  seems  to  move  on  a  central 
fixed  point  without  shifting  its  place  as  a  whole  within  the  orbit ;  four  move- 
ments are  possible:  (1)  lateral;  (2)  elevation  and  depression;  (3)  oblique 
movements  of  elevation  and  depression ;  (4)  rotation  about  a  sagittal  axis. 
The  ext.  and  int.  recti  produce  only  lateral  movements ;  the  sup.  and  inf.  recti 
have  their  line  of  direction  internal  to  the  centre  of  motion,  and.  so  produce 
not  only  elevation  and  depression,  but  also  inward  direction  and  slight  rota- 
tion :  this  is  corrected  by  the  oblique  muscles,  the  inf.  oblique  being  associated 
with  the  sup.  rectus,  and  sup.  oblique  with  the  inf.  rectus ;  the  sup.  oblique 
turns  the  cornea  down  and  out,  the  inferior  up  and  out. 

Around  the  orbit  is  soft  fat  and  the  capsule  of  Tenon,  forming  a  socket  at- 
tached in  front  to  the  ocular  conjunctiva:  a  large  lymph-space  is  between  it 
and  the  eye ;  it  is  pierced  by  the  eye-muscles  and  sends  a  tubular  prolongation 
upon  each.  The  suspensory  ligament  of  the  eye  is  a  thickening  of  the  lower 
part  of  the  capsule,  attached  at  each  end  to  the  orbital  margins  and  support- 
ing the  eye  in  its  socket. 

Muscles  of  Mastication. 

There  are  four  pairs,  two  outside  and  two  inside  the  jaw-bone.  The 
masseteric  fascia  is  a  part  of  the  deep  cervical,  covers  the  masseter  mus- 
cle, invests  the  parotid  gland  (parotid  fascia),  and  forms  the  stylo-max- 
illary ligament. 

^  1.  M.  masseter^  a  quadrate  muscle  with  two  parts:  the  superficial  part 
rises  from  the  sup.  maxilla,  malar,  and  lower  border  of  zygoma  for  its 
anterior  two-thirds  by  tendinous  bundles  which  project  between  the  mus- 
cular fasciculi  ;  it  passes  down  and  back  to  lower  half  of  jaw  from  angle 
to  third  molar  tooth  ;  the  deep  part  is  triangular,  and  passes  nearly  ver- 
tically from  the  posterior  third  of  zygoma,  lower  border,  and  from  all 
the  deep  surface  of  the  arch ;  inserted^  after  uniting  with  the  superficial 
part,  into  the  upper  half  of  the  ramus  and  coronoid :  this  is  almost 
wholly  covered  by  the  superficial  portion. 

There  may  be  a  bursa  between  these  two  parts. 

The  buccal  fat-pad  is  between  the  fore  part  of  the  masseter  and  the  bucci- 


172  MUSCLES   OF   THE   TRUNK. 

nator,  and  is  prolonged  into  the  zygomatic  fossa :  it  is  well  developed  in  the 
infant,  and  inappropriately  called  the  "sucking  pad." 

The  temporal  fascia  is  a  dense  apon.  covering  the  temporal  muscle 
above  the  zygoma :  it  is  attached  to  the  temporal  crest  of  the  frontal 
and  upper  temporal  line,  and  below  divides  into  two  layers  attached  to 
the  inner  and  outer  surfaces  of  the  Z3^gomatic  arch  ;  it  is  separated  from 
integument  by  a  lateral  projection  of  the  Galea  apon.  and  by  the  supe- 
rior and  anterior  auricular  muscles. 

2.  M.  temporalis  rises,  fan-shaped,  from  the  whole  of  the  temporal 
fossa,  not  its  anterior  malar  wall,  which  is  covered  with  fat,  from  the 
deep  surface  of  the  temporal  fascia,  and  may  blend  with  some  deep 
fibres  of  the  masseter.  The  anterior  fibres  are  nearly  vertical,  the  pos- 
terior nearly  horizontal ;  all  converge  to  a  tendon  which  is  inserted  into 
the  upper  and  anterior  borders  of  the  coronoid,  and  deeper  fibres  have 
a  fleshy  insertion  into  its  inner  surface  as  far  as  the  union  of  the  ramus 
and  body  of  jaw. 

M.  temporalis  minor  occasionally  goes  from  the  fibro-cartilage  of  the  temporo- 
maxillary  articulation  to  the  sigmoid  notch  of  the  lower  jaw. 

3.  M.  pterygoideus  externum  occupies  the  zygomatic  fossa,  and  rises  b^ 
two  heads,  the  upper  and  smaller  from  the  zygomatic  surface  of  the 
great  wing  of  the  sphenoid  and  infratemporal  crest;  the  lower  and 
larger  from  the  outer  surface  of  the  ext.  pterygoid  plate.  The  fibres 
from  both  pass  back,  converging  to  a  fossa  on  the  front  of  the  neck  of 
the  lower  jaw,  to  the  interarticular  cartilage  and  capsule.  A  venous 
plexus  is  between  its  upper  surface  arid  base  of  skull. 

M.  pterygoideus  proprius  is  a  vertical  band  from  the  infratemporal  crest  out- 
side the  ext.  pterygoid  to  the  outer  pterygoid  plate  or  tuberosity  of  palate- 
bone  or  sup.  maxilla. 

M.  pterygo-spinosus,  from  the  spine  of  the  sphenoid  to  the  outer  pterygoid 
plate  between  the  two  pterygoid  muscles :  this  is  frequently  a  pterygo-spinous 
ligament f  and  may  be  converted  into  bone. 

4.  M.  pterygoideus  internus  rises  also  by  two  heads — one  from  the 
pterygoid  fossa,  mostly  from  the  inner  surface  of  the  external  plate, 
from  the  tuberosity  of  the  palate  between  the  two  plates;  a  second 
small  slip  outside  the  ext.  pterygoid  muscle  from  the  tuberosities  of  the 
palate  and  sup.  maxilla:  fibres  pass  down,  back,  and  out  to  the  inner 
surfiice  of  the  ramus  between  the  angle  and  dental  foramen ;  it  is  dis- 
posed much  like  the  masseter. 

Nerves. — All  from  the  inferior  maxillary  division  of  the  fifth. 

Actions. — Masseter,  temporal,  and  int.  pterygoid  elevate  the  lower  jaw;  as  de- 
pression is  not  much  resisted,  it  is  accomplished  by  smaller  muscles,  chiefly 
the  digastric;  ext.  pterygoid  protrudes  the  lower  jaw,  or  alternately  produces 
a  grinding  of  molar  teeth  ;  it  may  also  assist  in  opening  the  mouth  when  the 
condyles  are  carried  forward  upon  the  artic.  eminences.  The  hinder  portion 
of  the  temporal  and  the  deep  part  of  the  masseter  retract  the  jaw. 


MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES.  173 

MUSCLES  AND  FASCIA  OF  THE  EXTREMITIES. 
The  Upper  Extremity. 

THE    SHOULDER. 
Describe  the  scapular  muscles  and  fasciae. 

The  deep  fascia  is  strong  and  tendinous  over  the  back  of  the  deltoid 
and  infraspinatus ;  the  infraspinatus  fascia  covers  the  teres  minor  and 
sphts  at  the  posterior  border  of  the  deltoid,  a  deep  layer  passing  to  the 
shoulder-joint  under  that  muscle,  a  superficial  la3^er  to  the  spine  of  the 
scapula  over  the  muscle. 

{a)    Vertical  Scapular  Muscles. 

M.  Deltoideus. — Origin^  in  three  portions:  an  anterior  from  the  front 
of  the  outer  third  of  the  clavicle,  a  middle  from  the  point  and  outer 
edge  of  the  acromion,  a  posterior  from  the  lower  border  of  the  scapular 
spine  and  triangular  surface  at  its  inner  end,  and  from  infraspinatus  fas- 
cia. These  converge  into  the  tendon  of  insertion  into  the  deltoid  tuber- 
cle of  the  humerus.  The  anterior  and  posterior  parts  run  by  long  fas- 
ciculi into  the  marginal  parts  of  the  tendon :  in  the  acromial  portion  most 
fibre.^  rise  in  a  bipenniform  manner  from  the  sides  of  four  tendinous 
septa ;  the  oblique  fibres  are  inserted  below  into  three  septa  which  come 
up  from  the  humerus  to  alternate  with  those  above.  Some  fibres  pass 
from  the  tip  of  the  acromion  to  the  tips  of  the  lower  septa,  and  some 
from  the  tips  of  the  upper  septa  directly  to  the  humerus. 

Fibres  continued  into  the  trapezius,  as  in  animals  lacking  clavicles ;  addi- 
tional slips  from  ext.  or  int.  border  of  scapula  (basio-deltoideus  Meckelii) ;  a 
prolongation  of  its  tendon  to  the  insertion  of  the  supinator  longus,  connected 
inseparably  with  the  pect.  major;  m.  acromio-davicularis  lat.  from  the  acro- 
mial end  of  the  clavicle  to  the  acromion  and  origin  of  deltoid ;  may  be  a 
subdeltoid  muscle. 

(h)  Posterior  Scapular  Muscles. 

1 .  31.  supraspinatus^  from  inner  part  of  supraspinous  fossa  to  region 
of  the  notch,  from  supraspinous  fascia  and  trans,  ligament;  adherent  to 
capsule  and  infraspinatus  tendon ;  inserted  into  the  upper  of  the  three 
facets  on  the  great  tuberosity  of  the  humerus. 

2.  M.  infraspinatus  ri^es  from  thQ  inner  two-thirds  of  the  infraspinous 
fossa,  from  the  infraspinatus  fascia,  and  under  surface  of  the  spine ;  fibres 
converge  to  a  tendon  concealed  within  the  muscle  and  inserted  into  the 
middle  facet  of  the  great  tuberosity.  It  may  be  inseparably  connected 
with  the  teres  minor. 

3.  M.  Teres  Minor.— Origin^  from  narrow  grooved  surface  or  dorsum 
of  scapula  close  to  axillary  border,  from  septa  between  it,  the  teres 
major,  and  infraspinatus ;  inserted  into  lowest  facet  on  great  tuberosity 
and  into  shaft  for  a  short  distance  below. 


174  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

May  be  a  bursa  under  its  insertion.  It  is  behind  the  long  head  of  the 
triceps  and  capsule ;  the  dorsal  scapular  artery  passes  between  it  and 
bone. 

(c)  Anterior  Scapular  Muscles. 

M.  Suhscapularis. — Origin^  by  muscular  and  tendinous  fibres  from 
venter  of  scapula  and  groove  along  the  axillary  border ;  insertion^  small 
tuberosity  of  humerus  and  into  shaft  for  a  short  distance.  As  in  the 
deltoid,  this  muscle  contains  two  sets  of  septa — one  from  the  origin,  and 
one  from  the  insertion  for  attachment  of  oblique  muscular  fibres.  Some 
fibres  from  the  axillary  border  of  the  muscle  are  usually  inserted  into  the 
capsule,  known  as  the  suhscapularis  minor. 

There  is  a  bursa  between  the  muscle  and  the  capsule,  and  often  another 
on  its  anterior  surface  (bursa  coraco-brachialis). 

Nerves. — Supra-  and  infraspinatus  by  suprascapular  nerve  from  fifth  and 
sixth  cervical ;  others  from  post,  cord  of  brachial  plexus,  detoid,  and  teres 
minor  from  fifth  and  sixth  cervical  through  circumflex  nerve;  suhscapularis 
by  fifth  and  sixth  cervical  through  upper  and  lower  subscapular  nerves. 

Actions. — Deltoid  abducts  arm  to  90°,  posterior  fibres  said  to  abduct  only  to 
45° ;  insertion  of  trapezius  corresponds  to  origin  of  deltoid,  so  that  the  two  are 
continuous  in  action :  anterior  part  of  the  deltoid  draws  the  humerus  forward 
and  rotates  in  ;  of  both  deltoids  crosses  the  arms  over  the  chest ;  posterior  part 
draws  humerus  backward  and  rotates  out ;  supra-,  infraspinatus,  and  suhscap- 
ularis steady  the  capsule  while  deltoid  acts.  The  supraspinatus  only  abducts. 
The  infraspinatus  rotates  out  and  carries  the  arm  back  when  it  is  raised.  The 
suhscapularis  rotates  in  and  carries  the  arm  forward  when  it  is  raised.  The 
teres  minor  rotates  the  raised  humerus  out  and  depresses  it.  All  act  as  liga- 
ments to  the  joint. 

THE  UPPER  ARM. 
Describe  the  muscles  and  fascise  of  the  upper  arm. 

The  aponeurosis  of  the  arm  (deep  fascia)  is  thin  over  the  biceps,  strong 
over  the  triceps,  and  is  attached  to  the  humerus  by  intermuscular  septa 
(ligg.  intermuscularia).  The  external  intermiiscular  septum  extends 
from  the  outer  epicondyle  and  supracondylar  ridge  to  the  deltoid  inser- 
tion :  it  is  pierced  by  the  musculo-spiral  nerve  and  sup.  profunda  artery. 
The  internal  intermuscular  septum  extends  from  the  inner  epicondyle 
and  inner  supracondylar  ridge  to  behind  the  coraco-brachialis  :  it  is 
pierced  by  the  anastomotica  magna  artery. 

The  internal  brachial  lig.  of  Struthers  is  a  fibrous  band  below  the  teres 
major  insertion  to  the  inner  epicondyle :  the  ulnar  nerve  and  inf  pro- 
funda artery  pass  between  this  band  and  the  int.  intermuscular  septum. 

(a)  Muscles  of  Anterior  Surface. 

First  Layer.— M.  Biceps  (brachii). — Its  short  or  inner  head  rises  with 
the  coraco-brachialis  from  the  coracoid ;  the  long  head,  from  the  upper 
end  of  the  glenoid  cavity  within  the  capsule  by  a  tendon  continuous  on 


THE   UPPER   ARM.  175 

each  side  with  the  glenoid  ligament:  these  two  heads  form  a  belly  in  the 
middle  and  lower  part  of  the  arm.  The  tendon  of  insertion  is  slightly 
twisted  and  attached  to  the  back  part  of  the  tuberosity  of  the  radius, 
separated  from  the  fore  part  by  a  bursa ;  may  be  a  second  bursa  between 
the  tendon  and  ulna.  From  the  inner  side  of  the  tendon  a  part  branches 
off  as  an  aponeurotic  band  or  semilunar  fascia  (lacertus  fibrosus,  p.  n.), 
and  blends  with  the  deep  fascia  of  the  forearm  stretched  across  the 
brachial  vessels  and  median  nerve. 

One  of  the  most  variable  muscles:  a  third  head  (10  per  cent,  of  cases)  rises 
from  humerus,  connected  with  brachialis  anticus  and  coraco-brachialis,  and 
inserted  into  coracoid  portion  of  muscle  and  semilunar  fascia :  this  is  usually 
outside  the  brachial  artery ;  a  head  may  come  from  outer  side  of  humerus, 
bicipital  groove,  or  great  tuberosity ;  may  be  two  additional  heads  or  even 
three.  It  may  give  off  a  slip  to  the  internal  intermusc.  septum  or  inner  con- 
dyle or  pronator  teres.  Absence  of  long  head  :  it  was  originally  extracapsu- 
lar, but  has  become  covered  by  the  coraco-humeral  lig.,  a  part  of  the  pect. 
minor.  The  semilunar  fascia  represents  an  ulnar  division  and  corresponds 
to  the  fascial  insertion  of  the  biceps  fem. 

Second  Layer. — 1.  M.  Coraco-hrachiah's.  —  Origin^  tip  of  coracoid 
between  pect.  minor  and  short  head  of  biceps,  conjoined  with  the  latter ; 
insertion^  inner  border  of  humerus  near  its  middle,  between  triceps  and 
brachialis  anticus;  higher  up  some  of  its  fibres  are  often  inserted  into  a 
fibrous  band  arching  over  the  lat.  dorsi  and  teres  major  tendons,  and  at- 
tached close  to  the  small  tuberosity.  It  is  usually  pierced  by  the  mus- 
culo-cutaneous  nerve. 

Many  varieties,  which  seem  to  indicate  it  is  formed  of  three  parts — viz.  (1) 
a  superior  short  part,  from  coracoid  to  small  tuberosity  (m.  coraco-capsularis  to 
capsule) ;  (2)  middle  part,  corresponding  to  the  muscle  usually  seen  ;  (3)  infe- 
rior part,  to  inner  epicondyle  or  supracondylar  process  (coraco-brachialis  minor). 
The  middle  part  is  most  constant  in  man,  but  is  usually  accompanied  by  a 
part  of  the  third,  with  the  musculo-cut.  nerve  between  them.  It  may  send  a 
slip  to  the  brachialis  anticus  or  internal  septum  or  int.  brachial  lig. 

2.  M.  hrachialis  anticus  (brachialis  internus,  p.  n.)  rises  from  the 
lower  half  of  i\iQ  front  of  the  humerus,  nearly  the  whole  of  the  int. 
intermuscular  septum,  and  upper  part  of  the  external :  it  embraces  the 
deltoid  insertion  by  two  processes,  the  outer  of  which  is  in  the  spiral 
groove  as  far  as  the  upper  limit  of  the  deltoid  tubercle.  It  is  adherent 
to  the  capsule  of ^  the  elbow-joint,  and  often  sends  a  slip  into  it,  and  is 
inserted  into  the  inner  part  of  the  rough  surface  at  the  junction  of  the 
coronoid  with  the  shaft  of  the  ulna. 

The  muscle  may  be  subdivided  into  two,  united  with  neighboring  muscles, 
or  send  a  slip  to  the  semilunar  fascia  or  radius. 

ip)  Posterior  Muscles  of  the  Upper  Arm. 

M.  extensor  triceps  occupies  the  whole  posterior  brachial  region.  Three 
heads  are  inserted  into  a  common  tendon  occupying  the  posterior  surface 


176  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

of  the  muscle  from  the  middle  of  the  arm  to  the  elbow.  The  middle  or 
long  head  (anconeus  longus — anconeus  was  a  term  applied  to  any  muscle 
attached  to  the  olecranon)  rises  from  the  inf  glenoid  tubercle  of  the 
scapula  and^  adjacent  portion  of  axillary  border :  this  forms  the  middle 
and  superficial  part  of  the  muscle  and  ends  on  the  inner  margin  of  the 
tendon.  The  external  head  (anconeus  brevis)  rises  above  the  spiral 
groove  and  from  an  aponeurotic  arch  of  the  external  intermusc.  septum 
as  it  crosses  it,  extending  to  the  teres  minor  insertion  above,  and  inserted 
into  the  upper  end  and  outer  border  of  tendon.  The  internal  or  deep 
head  (anconeus  internus)  rises  from  the  whole  posterior  surface  of  the 
humerus  below  the  spiral  groove,  from  the  lower  part  of  the  external  in- 
termusc. septum,  from  the  whole  of  the  internal,  as  high  as  the  teres  major : 
some  of  its  fibres  are  inserted  directly  into  the  olecranon,  but  most  join 
the  deep  surface  of  the  tendon.  The  common  tendon  is  inserted  into  the 
tuberosity  of  the  olecranon,  and  externally  a  band  is  prolonged  over  the 
anconeus  to  the  fascia  of  the  forearm  and  posterior  border  of  ulna :  it 
may  send  a  slip  to  the  capsule. 

On  removing  the  triceps  a  few  muscular  shps  are  sometimes  found 
from  the  bone  to  the  capsule,  analogous  to  the  subcrureus,  and  described 
by  some  as  distinct  from  the  triceps  called  the  suhanconeus. 

There  is  a  bursa  between  the  tendon  and  olecranon  or  in  the  tendon, 
sometimes  one  between  the  integument  and  tendon,  rarely  one  between 
the  tendon  and  ulnar  nerve  (retro-epi trochlear). 

Varieties. — Fourth  head  from  inner  part  of  humerus ;  a  slip  between  triceps 
and  lat.  dorsi,  the  anconeus  quintus  or  dorso-epitrochlearis  of  animals;  the  an- 
coneiis-epitrochlearis  from  the  inner  epicondyle  to  the  olecranon,  bridging  over 
the  ulnar  nerve  and  generally  present  as  a  band  of  fascia. 

Nerves. — Coraco-brachialis  by  branch  from  outer  cord  (7  c),  biceps  by  mus- 
culo-cut.  (5,  6  c),  brachialis  anticus  by  musculo-cut.  and  musculo-spiral,  tri- 
ceps by  musculo-spiral  (7,  8c.). 

Actions. — Biceps  flexes  arm  at  shoulder  and  forearm  at  elbow ;  after  prona- 
tion of  forearm  it  is  a  powerful  supinator  and  makes  tense  the  fascia  of  the 
forearm ;  its  inner  head  and  coraco-brachialis  draw  arm  in  as  well  as  up.  The 
brachialis  anticus  is  a  simple  flexor  at  the  elbow.  Triceps,  int.  and  ext.  heads 
are  extensors  at  the  elbow ;  the  long  head  extends  the  arm  on  the  scapula, 
keeps  the  head  of  humerus  in  place,  and  assists  in  extending  the  forearm. 
These  muscles  may  act  from  distal  fixed  points,  as  in  climbing. 

THE  FOREARM. 

Describe  the  muscles  and  fasciae  of  the  forearm. 

The  superficial  fascia  is  most  distinct  at  the  elbow,  contains  the  super- 
ficial veins,  and  below  connects  the  skin  with  palmar  fascia. 

The  aponeurosis  of  the  forearm  (deep  fascia)  is  composed  largely  of 
transverse  fibres,  strengthened  by  expansions  from  the  condyles  of  the 
humerus,  olecranon,  and  fascia  over  biceps  and  triceps.  The  anterior 
part  is  weaker  than  the  posterior,  and  continuous  below  into  the  ant. 
annular  ligament  (lig.  carpi  volare,  p.  n. ) :  it  sends  in  a  thin  layer  be- 


THE   FOKEARM.  177 

tween  the  superficial  and  deep  muscles.  The  posterior  portion  sends 
off  septa  between  the  muscles  and  forms  the  post,  annular  ligament  (lig. 
carpi  dorsale,  p.  n.). 

Anterior  Group ^  Pronato-flexor. 

Eight  muscles,  five  superficial  and  three  deep. 

Superficial  Layer. — All  from  a  common  tendon  in  the  following 
order  from  without  in  : 

1.  M.  pronator  teres  rises  by  two  heads,  the  larger  from  the  upper 
part  of  the  inner  condyle,  common  tendon,  fascia,  and  intermuscular 
septum ;  second  head,  thin  and  deep,  from  inner  margin  of  coronoid ; 
insertion,  middle  of  outer  surface  of  radius.  The  ulnar  artery  is  beneath 
this  muscle,  and  median  nerve  between  its  heads. 

Liable  to  be  injured  in  the  "back  stroke"  of  lawn  tennis.  Coronoid  head 
maybe  absent;  slip  from  intermusc.  septum  above  inner  condyle  or  from 
supracondylar  process;  additional  head  from  biceps  or  brach.  anticus. 

2.  M.  flexor  carpi  radialis  (m.  radialis  internus)  rises  from  the  com- 
mon tendon,  fascia  of  forearm,  and  septa  between  it  and  the  pron.  teres, 
palmaris  longus,  and  flex,  sublimis  ;  tendon  begins  below  middle  of  fore- 
arm, passes  through  a  special  compartment  of  the  ant.  ann.  lig.,  through 
a  groove  in  the  trapezium ;  inserted  into  the  base  of  the  second  meta- 
carpal bone,  anterior  surface,  and  usually  by  a  small  slip  to  the  base  of 
the  third. 

Absence  of  muscle ;  inserted  into  ann.  lig.,  trapezium,  or  fourth  metacarpal ; 
receives  slip  from  biceps  or  its  fascia,  coronoid  process,  or  oblique  line  of 
radius. 

3.  M.  palmaris  longus  is  placed  between  the  ulnar  and  radial  flexors 
of  the  carpus,  resting  upon  the  flex.  subl.  ;  rises  from  common  tendon, 
fascia,  and  septa,  forming  a  short  muscular  belly  ending  in  a  slender 
tendon,  inserted  into  the  palmar  fascia,  and  sends  a  slip  to  the  abductor 
poll. ,  sometimes  one  to  the  httle  finger  muscles. 

Most  variable  muscle  of  body,  lacking  oh  both  sides  in  one-third  of  the  cases, 
on  one  side  in  one-half  the  cases  (Hallett).  Muscular  belly  may  occupy  the 
middle  of  the  tendon,  lower  end,  both  ends,  or  be  absent ;  may  be  double  or 
have  additional  origin  from  coronoid  or  radius.  Inserted  into  fascia  of  fore- 
arm, flex,  carpi  uln.,  pisiform,  scaphoid,  or  little  finger  muscles.  This  muscle 
with  the  central  part  of  the  palmar  fascia  was  a  superficial  flexor  of  the 
fingers,  but  has  been  reduced  by  the  development  of  the  other  flexors. 

4.  M.  flexor  carpi  idnaris  (m.  ulnaris  int.)  is  the  innermost  of  the 
superficial  group ;  rises  by  two  heads,  one  from  the  common  tendon,  and 
one  from  the  inner  side  of  the  olecranon  and  upper  two-thirds  of  the 
post,  border  of  the  ulna,  connected  with  the  deep  fascia  of  the  forearm  ; 
muscular  fibres  end  in  a  tendon  along  its  anterior  margin ;  inserted  into 
the  pisiform,  by  a  small  band  to  the  ant.  ann.  lig. ,  and  prolonged  by  the 

12— A. 


178  MUSCCES   AND   FASCIA   OF   THE   EXTREMITIES. 

piso-metacarpal  and  piso-uncinate  ligaments  to  the  fifth  metacarpal  and 
unciform.: 

The  ulnar  nerve  and  post,  ulnar  recurrent  artery  pass  between  its  two 
heads :  the  pisiform  throws  this  tendon  forward,  so  that  the  ulnar  pulse 
cannot  be  felt  so  well  as  the  radial. 

Additional  sHp'from  coronoid;  insertion  into  ann.  lig.  or  fourth  and  fifth 
metacarpals.  *  Monro  thinks  there  is  a  bursa  between  its  tendon  and  the 
pisiform.    , 

5.  M.  flexor  sublimis  digitorum  (perforatus),  placed  behind  the  pre- 
ceding, rises  &!/ three  heads :  (1)  inner  condyle  by  common  tendon,  fibrous 
septa,  and  int.  lateral  lig.  ;  (2)  inner  margin  of  coronoid;  (3)  ant.  oblique 
line  of  radius ;  divided  below  into  four  parts  ending  in  tendons  inserted 
into  the  second  phalanges  of  the  four  inner  digits.  Through  the  ann. 
lig.  they  are  placed  in  pairs :  the  anterior  pair  are  for  the  ring  and  mid- 
dle fingers,  the  posterior  for  the  index  and  little  fingers.  In  the  palm 
they  diverge  and  enter  a  sheath  with  the  flex,  prof  ;  opposite  the  bases 
of  the  first  phalanges  the  tendon  divides  and  folds  round  the  deep  flexor, 
and  is  reunited  behind  it ;  the  two  portions  again  separate  and  pass  on 
each  side  to  the  middle  of  the  lateral  border  of  the  second  phalanx. 

The  arrangement  into  pairs  corresponds  to  a  division  into  layers,  which  can 
be  separated  nearly  to  the  inner  condyle;  the  middle  finger  receives  the 
radial  head,  the  ring-finger  tendon  is  joined  by  a  slip  from  the  deep  layer; 
this  deep  layer  is  a  digastric  muscle  from  the  inner  condyle,  int.  lat.  lig.,  and 
coronoid ;  the  conical  belly  ends  in  a  tendon  above  the  middle  of  the  fore- 
arm, from  which  rise  (1)  a  fleshy  slip  to  the  ring-finger  tendon,  (2)  a  belly 
for  the  index-finger  tendon,  (3)  small  belly  furnishing  the  little-finger  ten- 
don. There  is  usually  a  slip  from  the  condylo-ulnar  head  to  the  flex.  long, 
poll,  tendon. 

Varieties. — Absence  of  radial  head ;  of  little-finger  portion,  which  may  be 
replaced  by  a  slip  from  ann.  lig.,  palmar  fascia,  flex,  prof.,  or  fourth  lumbri- 
calis ;  a  frequent  slip  to  the  flex.  prof.  A  bursa  in  its  tendinous  origin  or  be- 
tween it  and  the  pron.  teres  in  1  per  cent,  of  cases. 

Deep  Muscles. 

First  Layer.  — 1 .  M.  flexor  profundus  digitorum  ( perforans). — Origin 
(not  from  humerus),  three-fourths  of  inner  and  anterior  surface  of  ulna, 
from  not  quite  the  ulnar  half  of  the  interosseous  membrane  for  the  same 
distance,  and  from  an  apon.  attached  to  the  post,  border  of  the  ulna,  com- 
mon to  it  and  flex.  c.  ulnaris.  Only  one  tendon  (for  inderx  finger)  sep- 
arates above  the  wrist ;  in  the  palm,  as  the  tendons  diverge,  they  give 
origin  to  the  lumbricales ;  over  the  first  and  second  phalanges  the  tendon 
is  bound  down  by  an  osseo-aponeurotic  sheath,  and  opposite  the  first 
phalanx  it  passes  through  an  opening  in  the  flex.  subl.  tendon,  and  is 
finally  inserted  by  an  expanded  end  into  the  base  of  the  last  phalanx  : 
over  the  middle  and  last  phalanx  its  tendon  is  marked  by  a  longitudinal 
furrow  or  cleft. 

The  index-finger  portion  is  usually  separate  throughout,  and  comes  mostly 


THE   FOREARM.  ^^ 


jla-finger  portions 


from  the  interosseous  membrane ;  between  the  ring-  ay  iittj 
a  considerable  part  of  the  inner  surface  of  the  ulna  isjrftfi 
tachment.  a 

M.  accessorius,  from  the  common  tendon  of  the  supemcial  muscles. 

The  sheaths  of  the  flexor  tendons  are  opposite  t^^^rst  and  second 
phalanges,  and  formed  of  strong  transverse  bands,  u^i^Mwinalia ;  o^,^^ 
posite  the  joints  the  bands  change  into  a  thin  mernbra^^^^gi^tl^jll^ 
by  obUque  decussating  fibres,  so  that  there  are  anniday^^ftitiiSiiMS^f^ 
fibres,  crudal  and  ohlique.     The  sheath  has  a  synovial  lining  containing 
small  folds,  vincula  tendimim  or  ligg.  mucosa,  passing  between  tendons 
and  bones.     There  are  two  sets:  Ugamenta  hrevia.  broad,  four-sided, 
and  membranous,  passing  between  both  the  superficial  and  deep  tendons 
near  their  insertions  and  the  lower  part  of  the  phalanx  just  above  the 
joint-capsule  ;  the  Ugamenta  longa^  less  constant,  join  the  tendons  at  a 
higher  level.     Contained  in  the  lig.  breve  of  the  deep  flexor  is  a  small 
band  of  yellow  elastic  tissue,  lig.  suhflavum,  passing  from  the  tendon  to 
the  head  of  the  second  phalanx. 

2.  M.  flexor  longus  pollicis  rises  from  the  anterior  surface  of  the  radius, 
from  its  oblique  line  to  the  edge  of  the  pron.  quad.,  and  from  the  adja- 
cent part  of  the  interosseous  membrane,  and  usually  (27  out  of  36  cases) 
receives  a  slip  (fasciculus  exilis)  from  the  inner  epicondyle  or  coronoid. 
The  tendon  passes  between  the  sesamoid  bones  of  the  thumb  and  enters 
a  canal  similar  to  that  of  the  other  flexors,  to  be  inserted  into  the  base  of 
the  last  phalanx  of  the  thumb.  Its  complete  separation  from  the  flex, 
prof  is  characteristic  of  man. 

May  have  a  slip  from  flex.  subl.  or  prof,  or  pronator  teres  ;  may  be  inserted 
into  index  finger  or  first  lumbricalis. 

M.  flexor  carpi  radiaUs  brevis  oy  profundus  (6  out  of  70)  rises  from  outer  sur- 
face and  anterior  border  of  radius  between  insertions  of  pron.  teres  and  supi- 
nator longus ;  insertion,  very  variable  into  tendon  of  flex  c.  rad.  or  bones  of 
carpus  or  metacarpus ;  more  often  present  in  the  right  arm. 

31.  ulnaris  int.  brevis  (m.  flex.  c.  ulnaris  brevis)  is  a  corresponding  muscle 
from  lower  fourth  of  anterior  surface  of  ulna  to  unciform. 

Second  Layer. — M.  pronator  quadratus^  close  to  bones  behind  the 
last  two  muscles,  quadrilateral  and  flat,  from  pronator  ridge  and  inner 
part  of  anterior  surface  of  ulna  for  lower  fourth,  from  radio-carpal  joint ; 
inserted  into  fore  part  and  inner  side  of  radius  for  less  than  its  fourth. 

Maybe  absent,  subdivided  into  two  or  three  layers,  extended  further  up  than 
usual,  prolonged  down  as  radio-carpal  or  ulno-carpal  muscle ;  a  slip  from  ulna 
to  trapezium  or  scaphoid  =  m.  cubito-carpeus.  Being  bound  to  radio-ulnar 
capsule,  it  prevents  its  folding  in  pronation  movements. 

Nerves. — Six  and  one-half  of  the  above  muscles  by  the  median  nerve,  one 
<ind  one-half  by  the  ulnar.  Pron.  teres,  flex.  c.  rad.,  palm,  longus,  condylo- 
ulnar  head  of  flex.  subl.  receive  median  branches  near  elbow ;  radial  head  of 
flex.  subl.  and  belly  for  index  finger  have  separate  twigs  ;  flex.  long,  poll.,^  pron. 
quad.,  and  outer  half  of  flex.  prof,  by  ant.  interosseous  br.  of  median.  Flex. 
c.  ulnaris  and  inner  half  of  flex.  prof,  by  ulnar. 


180  MUSCLES   AND   FASCI-J]   OF   THE   EXTREMITIES. 

Radial  Group, 
Three  in  number,  from  lower  third  of  arm  and  upper  third  of  forearm 
in  an  almost  continuous  row. 

1 .  M.  supinator  longus  (brachio-radialis)  rises  from  the  upper  two- 
thirds  of  the  ext.  supracondylar  ridge  of  the  humerus  and  ext.  inter- 
muscular septum,  limited  above  by  the  spiral  groove :  thin  fleshy  belly 
ends  at  middle* of  forearm  in  a  flat  tendon  which  expands  at  its  insertion 
into  the  outer  side  of  the  radius  at  base  of  styloid  process ;  its  inner  edge 
is  united  by  fascia  to  the  flex.  c.  rad.  ;  it  sends  some  fibres  to  the  apon- 
eurosis on  the  back  of  the  forearm. 

Muscle  doubled  or  absent;  united  with  brach.  anticus ;  tendon  splits  into 
slips  inserted  together  or  at  a  distance  from  each  other  ;  inserted  into  middle 
of  radius,  tendon  of  biceps  ;  slips  to  extensors  of  thumb. 

M.  sup.  long,  accessorius  (1  per  cent,  of  cases)  rises  either  above  or  below  the 
origin  of  the  normal  muscle  and  passes  between  it  and  the  mm.  radiales  to 
the  tuberosity  of  the  radius. 

2.  M.  extensor  carpi  radialis  longior  rises  from  the  lower  third  of  the 
ext.  supracondylar  ridge  and  ext.  intermusc.  septum  and  a  few  fibres 
from  the  common  tendon ;  inserted  into  base  of  second  metacarpal. 

3.  M.  Extensor  Carpi  Radialis  Brevior. — Ori'gm,  by  common  extensor 
tendon  from  outer  condyle,  septa,  ext.  lat.  lig. ,  fascia,  and  a  fibrous  arch 
over  the  radial  n.  and  rad.  recurrent  vessels ;  insertion^  base  of  meta- 
carpal bone  of  middle  finger. 

Where  these  tendons  are  crossed  by  the  first  two  thumb  extensors  a  bursa 
is  interposed ;  there  is  another  under  each  tendon  at  its  insertion ;  often  one 
between  the  short  rad.  extensor  and  supinator  brevis. 

Each  tendon  may  be  split  into  two  or  three  at  its  insertion ;  either  may  be 
inserted  into  both  the  second  and  third  metacarpals  or  send  a  slip  to  the 
fourth.    The  two  muscles  may  be  united  more  or  less  completely. 

M.  extensor  c.  rad.  intermedins^  from  humerus  or  normal  extensors  to  second 
and  third  metacarpals  or  both. 

M.  extensor  c.  r^d.  accessorius,  from  humerus  near  attachment  of  long  radial 
extensor,  inserted  by  two  slips  into  abd.  poll,  or  first  dorsal  inteross.  and  into 
metacarpal  bone  of  thumb. 

Posterior  Group. 

Two  layers,  muscles  of  superficial  layer  inserted  into  ulnar  edge  of 
forearm  and  hand  and  into  fingers  from  fifth  to  second  inclusive ;  of  deep 
layer  into  radial  edge  of  forearm  and  hand  and  two  outer  fingers. 

Superficial  Layer. — 1.  M.  Exiensor  Communis  Digitorum. — Origin 
(from  neither  ulna  nor  radius),  common  tendon,  fascia,  and  septa;  there 
are  three  fleshy  bellies,  the  innermost  divided  into  two,  four  passing  under 
the  post.  ann.  lig. ;  the  first  and  second  pass  to  the  index  and  middle  fin- 
gers connected  by  a  weak  band,  always  transverse ;  the  first  is  joined  by 
the  extens.  indicis  tendon  at  the  metacarpo- phalangeal  joint ;  the  third 
runs  to  the  ring  finger  and  sends  a  sHp  to  the  middle  finger  tendon  ;  the 
fourth  divides,  the  outer  larger  part  going  to  the  ring  finger,  the  inner 


PLATE  XIII. 


Fig.  1.— To  face  page  180. 


Eing  Finger  of  the  Eight  Hand,  with  its  Adductor  Interosseous  Muscle  : 
a,  one  belly  of  the  Interosseous,  attached  at  b  to  the  first  phalanx ;  c,  the 
other  belly  of  the  Interosseous,  attached  by  d,  d,  its  tendon,  to  the  posterior 
surface  of  the  second  and  third  phalanges,  and  joined  to  e,  e,  the  tendon  of 
the  Extensor  communis  (Duchenne). 


Fig.  2. — To  face  page  180. 


Transverse  Section  through  the  Wrist,  showing  the  annular  ligaments 
and  the  canals  for  the  passage  of  the  tendons. 


PLATE  XIV. 

Fig.  1.— To  face  page  185.  Fig..  2.— To  face  page  185. 


The  Dorsal  Interossei  of  Left  Hand.  The  Palmar  Interossei  of  Left  Hand^ 


THE   FOREARM.  181 

part  joining  the  outer  division  of  the  extens.  min.  dig.  tendon  :  this 
fourth  is  the  smallest  tendon,  and  receives  muscular  fibres  as  far  as  the 
wrist. 

Opposite  the  metacarpo-phalangeal  joints  the  tendons  are  bound  down 
by  transverse  fibres  from  the  front  of  the  joint,  ligg.  dorsalia;  the  tendon 
expands,  is  joined  by  a  slip  from  the  interossei,  and  on  the  radial  side  by 
the  insertion  of  a  lumbrical  muscle,  forming  a  broad  aponeurosis,  which 
divides  at  the  lower  part  of  the  first  phalanx  into  three  slips — a  central 
thin  one  for  the  base  of  the  second,  while  the  two  lateral  parts  join  and 
are  inserted  into  the  base  of  the  last  phalanx. 

Varieties. -^De^ciencj  of  one  or  more  tendons,  especially  for  fifth  finger; 
more  often  an  increase,  especially  for  the  index  and  middle  fingers ;  a  doub- 
ling or  tripling  of  all  the  tendons ;  a  slip  to  the  thumb. 

2.  M.  exteftisor  mmimi  digiti  (extens.  dig.  quinti  propr.)  rises  from 
superficial  and  deep  fascia  of  forearm,  from  septa  between  it  and  the 
common  and  ulnar  extensors:  its  tendon  is  in  a  groove  between  the 
radius  and  ulna,  and  splits  into  two  on  the  back  of  the  hand,  the  outer 
being  joined  by  a  slip  from  the  fourth  common  extens.  tendon,  and  both 
parts  end  on  the  little  finger,  like  the  other  extensor  tendons. 

Rises  by  a  thin  slip  from  the  common  tendon  in  5  per  cent,  of  cases ;  tendon 
of  insertion  undivided  in  10  per  cent,  of  cases;  gives  a  slip  to  ring  finger  in 
6  per  cent. ;  fusion  of  belly  with  common  extensor  in  4  per  cent. ;  absence 
rare. 

3.  M.  Extensor  Carpi  Ulnaris  (ulnaris  externus). — Origin^  common 
tendon,  septa,  fascia  of  forearm,  which  is  connected  with  elbow-joint 
capsule  and  anconeus ;  its  belly  in  its  middle  third  is  bound  to  the  pos- 
terior border  of  the  ulna  by  aponeurosis,  and  may  receive  fibres  from 
this  fascia ;  insertion,  tuberosity  of  base  of  fifth  metacarpal.  A  bursa 
is  under  its  tendon  of  origin  in  one-fourth  of  the  cases. 

In  52  per  cent,  of  cases  a  slip  is  continued  anteriorly  over  the  oppo- 
nens  min.  dig.  to  the  fascia  over  that  muscle,  to  the  metacarpal  bone  or 
first  phalanx  of  the  little  finger  (analogue  of  per.  brevis  of  little  toe). 

Muscle  may  be  double,  reduced  to  a  tendinous  band,  inserted  into  fourth 
or  third  metacarpal. 

M.  ulnaris  quinti  digiti,  from  post,  surface  of -lower  half  of  ulna  to  base  first 
phal.  of  little  finger :  is  represented  in  44  per  cent,  by  a  dorsal  slip  from  ex- 
tens,  uln.  tendon  to  metacarpal  bone,  or  first  phal.  or  extens.  tendon  of  little 
finger. 

4.  M.  anconeus  (quartus)  fills  the  space  between  the  triceps  and  extens. 
carp.  uln.  ;  is  flat  and  triangular,  covered  by  fascia  connected  with  the 
triceps ;  rises  by  a  narrow  tendon  from  a  fossa  on  the  inner  and  posterior 
part  of  the  ext.  condyle ;  upper  fibres  are  transverse,  rest  pass  obliquely 
down  and  in  to  the  radial  aspect  of  the  olecranon  and  adjacent  upper 
third  of  the  ulna.     As  a  rule,  its  superior  fibres  are  continuous  with 


182  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

those  of  the  int.  head  of  the  triceps.     A  bursa  is  found  under  its  tendon 
of  origin,  not  in  children. 

Deep  Layer.— 1.  M.  Supinator  Brevis. — Origin^  ext.  lat.  lig., 
orbicular  lig. ,  supinator  ridge,  bicipital  hollow  of  ulna,  and  for  a  short 
distance  on  outer  border  of  ulna,  from  fascia  covering  it,  which  is  con- 
nected with  the  ext.  condyle :  it  regularly  consists  of  two  layers  separated 
by  the  post,  interosseous  n.  ;  fibres  pass  sling-like  around  upper  part  of 
radius  to  be  inserted  into  a  third  of  its  length,  limited  by  the  ant.  and 
post,  oblique  lines,  to  its  neck  and  elbow-joint  capsule. 

Anterior  fibres  may  have  separate  insertion  into  the  orbicular  Jig. ;  inser- 
tion into  biceps  or  tuberosity  of  radius. 

2.  M.  Extensor  OssisMetacarpi  Pollicis  (abd.  poll,  longus). —  Origin^ 
upper  part  outer  division  of  posterior  surface  of  ulna  below  supinator 
brevis,  from  middle  third  of  i30sterior  surface  of  radius  and  interosseous 
membrane  between ;  inserted  into  radial  side  of  base  of  metacarpal  bone 
of  thumb,  and  commonly  by  a  slip  into  the  trapezium,  its  tendon  usually 
splitting. 

3.  M.  extensor  longus  pollicis  (ext.  secundi  intern,  poll.)  rises  below 
the  extensor  ossis  on  the  middle  third  of  the  ulna  and  from  the  inteross. 
memb.  for  about  1  inch :  its  tendon  passes  over  the  radial  extensors,  and 
is  inserted  into  the  base  of  the  last  phalanx  of  the  thumb.  There  is  a 
tendency  for  it  to  divide  into  three  parts,  as  in  case  of  extensor  comm. 
tendons,  but  all  three  converge  to  the  base  of  the  last  phalanx. 

4.  M.  Extensor  India's  Proprius  (m.  indicator). — Origin,  from  ulna 
below  extensor  long.  poll. ,  and  slightly  from  interosseous  membrane  and 
fascia  over  extens.  c.  uln.  ;  unites  with  the  common  extensor  tendon  for 
the  index,  and  forms  the  usual  insertion.  This  and  the  ext.  min.  dig. 
tendon  are  always  on  the  ulnar  side  of  the  common  extensor  tendons. 

Earely  absent,  often  double,  and  one  slip  may  pass  to  the  thumb,  ring 
finger,  or  middle  finger,  forming  an  extensor  medii  digiti  which  can  rise  sepa- 
rately from  the  ulna  or  post  ann.  lig. 

M.  extensor  brevis  dig.  manits,  from  back  of  wrist-joint,  carpus,  or  metacarpus, 
sending  tendons  to  one,  two,  or  three  fingers. 

5.  M.  Extensor  Brevis  Pollicis  (ext.  primi  interned,  poll.). — Origin^ 
small  part  of  inteross.  memb.  and  radius  below  the  middle,  next  below 
the  extensor  ossis ;  insertion^  proximal  end  of  first  phal.  of  thumb. 

Varieties  in  thumb  extensors  in  1  out  of  6  cases;  most  often  in  extens. 
ossis ;  insertion  into  short  thumb-muscles.  Extens.  brevis  poll,  is  peculiar  to 
man,  lacking  in  5  per  cent.,  fused  as  it  were  with  the  extens.  ossis ;  it  may  be 
united  with  the  long  extensor.  The  long  extensor  is  often  double  ;  may  send 
a  slip  to  the  common  extensor  or  indicator.  May  be  another  extensor  between 
the  indicator  and  extens.  long,  poll.,  with  insertion  into  both  digits ;  this  is 
normal  in  the  dog. 

Nerves. — For  the  radial  and  posterior  groups  wholly  by  the  musculo-spiral ; 
the  anconeus,  sup.  longus,  and  extens.  carp.  rad.  long,  by  that  nerve  before  it 
divides;  all  the  others  by  its  post,  interosseous  branch. 


THE   HAND.  183 

Three  nerves,  therefore,  supply  all  the  muscles  of  the  forearm — median  and 
ulnar  anteriorly  (flex.  c.  ulu.  and  inner  half  of  flex.  prof,  by  ulnar),  musculo- 
spiral  externally  and  posteriorly.  •* 

THE  HAND. 
Describe  the  muscles  and  fasciae  of  the  hand. 

Fascia  of  the  dorsum  is  a  thin  layer  prolonged  from  the  post.  ann. 
lig.  and  blending  with  the  extensor  expansions  over  the  fingers ;  deeper 
than  this  the  interossei  are  covered  by  thin  aponeuroses. 

Fascia  of  the  palm  (volar  aponeurosis)  consists  of  a  strong  central 
part  and  two  lateral  portions  which  cover  the  short  muscles  of  the  thumb 
and  little  finger.  The  central  portion  is  the  part  commonly  called  palmar 
fascia :  it  consists  of  fibres  mostly  prolonged  from  the  palm.  long. ,  some 
from  the  ann.  lig.,  thus  forming  two  superficial  layers  with  vertical  fibres, 
between  which  is  the  palm,  brevis  muscle ;  ^  there  is  a  deep  layer  of 
transverse  fibres.  Below  the  fascia  divides  into  four  processes  to  join 
the  digital  sheaths ;  offsets  are  sent  back  to  the  deep  trans,  lig.  at  the 
heads  of  the  metacarpals,  forming  a  short  canal  above  each  finger  for 
the  flexors.  Between  the  processes  the  transverse  layer  of  fascia  covers 
the  lumbrical  muscles,  digital  vessels,  and  nerves,  passing  over  to  the 
thumb  and  forefinger.  At  the  clefts  of  the  fingers  a  transverse  band 
is  called  the  superficial  trans,  lig.^  or  Gerdy's  fibres.  The  interossei 
muscles  also  have  a  separate  fascia  continued  below  into  the  deep  trans, 
lig. 

(a)   On  the  Dorsum. 

Extensor  tendons  already  described. 

(b)  Muscles  of  Volar  Surface. 

Superficial  Muscles. — M.  palmaris  hrevis^  thin  and  subcutaneous, 
rises  from  ann.  lig.  and  deep  layer  of  longitudinal  fibres  of  palmar  fascia, 
and  ends  in  a  vertical  line  in  tl^e  fascia  covering  the  ball  of  the  little 
finger,  and  sometimes  in  the  skm. 

Deep  Muscles. — Median. — Carpal  Bursce. — As  the  superficial  and 
deep  flexors  and  flex.  long.  poll,  enter  the  hollow  of  the  hand  they  are 
bound  into  one  tube  lined  by  synovial  tissue;  a  loose  synovial  sac  is 
formed,  passing  up  to  the  level  of  the  radio-carpal  joint  and  prolonged 
down  the  inner  tendons  to  the  digital  sheath  of  the  little  finger,  open- 
ing into  it  generally.  The  sheath  for  the  tendon  of  the  thumb  is  gen- 
erally separated  from  the  large  sac  by  a  sagittal  septum  behind  the  me- 
dian nerve;  the  bursa . extends  but  a  short  distance  on  the  index  and 
middle-finger  tendons. 

The  mm.  lumhricales  (fiddler's  muscles)  are  four  tapering  fasciculi 
passing  from  the  deep  flexor  tendons  each  to  the  dorsal  expansion  of  the 
common  extensor  on  the  radial  side  of  the  first  phalanx:  each  rises 
from  the  radial  side  and  radial  part  of  the  ant.  surface  of  the  deep 


184  MUSCLES   AND   FASCIA   OF   THE    EXTREMITIES. 

flexors,  and  the  inner  two  also  from  their  ulnar  borders — i.  e.  have  two 
heads. 

Varieties. — A  diminution  or  increase:  one  finger  may  have  two  inserted 
into  it :  the  fourth  may  take  the  place  of  the  fourth  superficial  flexor. 

Muscles  of  the  Ball  of  the  7'humb.— These  constitute  the  thenar  emi- 
nence; great  variety  of  description.     (See  Quain  and  Henle.) 

1.  M.  Abductor  Pollicis  (hreYis).  —  Oi-fgin,  front  of  ann.  lig.,  ridge  of 
trapezium  or  tuberosity  of  scaphoid ;  insertion,  base  of  first  phal.  of 
thumb,  radial  border,  and  sends  a  slip  to  the  extensor  tendons.  (Henle 
calls  this  one  belly,  and  what  is  described  below  as  the  outer  head  of  the 
flexor  brevis  he  calls  the  other  belly  of  the  abductor). 

2.  M.  Flexor  Brevis  Follids.— Outer  or  superficial  head  from  outer 
two-thirds  of  ann.  lig.  to  outer  side  of  base  of  first  phalanx,  having  a 
sesamoid  bone  developed  in  it :  inner  or  deep  head  is  very  small,  and 
between  the  add.  obliquus  and  outer  head  of  first  dorsal  interosseous ; 
rises  from  ulnar  side  of  the  first  metacarpal ;  inserted  into  inner  side  of 
base  of  first  phalanx. 

3.  M.  adductor  pollicis  Quain  describes  in  two  parts,  separated  by  the 
radial  artery  as  it  enters  the  palm.  The  adductor  obliquus  pollicis  (caput 
obliquum,  p.  n.),  largest  of  thumb  muscles,  rises  from  the  upper  ends 
of  the  second  and  third  metacarpals,  os  magnum,  ant.  carpal  ligaments, 
and  sheath  of  flex.  c.  rad. :  it  passes  on  the  inner  side  of  the  long  flexor 
tendon  to  the  inner  side  of  the  base  of  the  first  phalanx,  uniting  with 
the  adductor  transversus  and  deep  head  of  flexor  brevis.  The  inner 
sesamoid  bone  is  developed  in  it.  A  considerable  fasciculus  passes  be- 
hind the  long  flexor  to  join  the  superficial  head  of  the  flexor  brevis  and 
outer  sesamoid  bone.  (This  muscle  is  usually  described  as  the  inner 
head  of  the  flexor  brevis. ) 

The  adductor  transversus  poll,  (caput  transversum,  p.  n. )  rises  from 
the  lower  third  of  the  front  of  the  third  metacarpal  bone ;  inserted  into 
inner  side  of  base  of  first  phalanx  of  thumb,  and  the  common  insertion 
sends  a  slip  to  the  long  extensor. 

4.  M.  opponens  pollicis^  beneath  the  abductor,  rises  from  the  ann.  lig. 
and  outer  side  of  ridge  of  trapezium ;  inserted  by  an  upper  layer  into 
the  whole  length  of  the  first  metacarpal  bone,  radial  border,  and  by  its 
deeper  layer  into  the  head  of  the  bone  and  radial  part  of  its  palmar 
surface. 

Muscles  of  Ball  of  Little  Finger. — These  three  muscles  constitute  the 
hypothenar  efiuinence. 

1.  M.  abductor  minimi  digiti  (abd.  dig.  quinti)  rises  from  the  lower 
border  and  inner  surface  of  the  pisiform,  almost  a  continuation  of  the 
flex.  c.  uln.  ;  insertion,  base  of  first  phalanx  of  little  finger,  ulnar  side, 
and  into  a  sesamoid  bone,  sending  a  slip  to  the  extensor  tendon. 

2.  M.  flexor  brevis  min.  digiti  is  separated  from  the  abductor  by  deep 
branches  of  the  ulnar  nerve  and  artery,  and  rises  from  the  annular  lig. 
and  tip  of  unciform  process ;  inserted  into  the  base  of  the  first  phalanx 


THE   HAND.  185 

by  means  of  a  tendinous  arch  passing  over  the  flexors,  attached  to  the 
radial  and  ulnar  borders  of  the  base.  May  be  absent  or  fused  with  the 
abductor. 

3.  M.  opponens  minimi  digiti,  from  ann.  lig.  and  unciform  process  to 
whole  length  of  ulnar  side  of  fifth  metacarpal  and  anterior  surface  of  its 
head. 

Mm.  Interossei — The  dorsal  inter ossei  are  four  in  number,  one  for 
each  space,  not  rising  above  the  level  of  the  bones,  and  numbered  from 
without  inward.  Each  rises  from  the  two  bones  between  which  it  is 
placed,  most  extensively  from  that  supporting  the  finger  upon  which  it 
acts.  The  tendon  is  inserted  partly  into  the  base  of  the  first  phalanx 
and  partly  into  the  extensor  tendon :  they  abduct  the  fingers  from  the 
middle  line ;  two  are  inserted  into  the  middle  finger,  one  on  either  side, 
one  into  the  radial  side  of  the  index,  and  one  into  the  ulnar  side  of  the 
ring.  The  first  dorsal  interosseous  is  larger  than  the  others,  called  the 
abductor  indicis :  its  outer  head  comes  from  the  proximal  half  of  the 
ulnar  border  of  first  metacarpal,  its  inner  from  the  whole  length  of  the 
radial  border  of  second  metacarpal. 

The  palmar  interossei  are  three  in  number,  are  adductors,  and  each 
rises  from  the  lateral  surface  of  the  metacarpal  of  the  finger  on  which  it 
acts.  They  terminate  like  the  dorsal  tendons.  The  first  belongs  to  the 
ulnar  side  of  the  index,  the  second  and  third  to  the  radial  sides  of  the 
ring  and  little  fingers.  Henle  describes  four  palmar  interossei,  the 
first  being  the  inner  head  of  the  flex,  brevis  poll. ,  as  described  above. 
Small  bursae  are  between  the  interossei  tendons  and  metacarpo-phal. 
joints. 

Varieties.— Talm.  brevis  seldom  absent :  a  slip  to  abd.  poll,  from  skin  over 
thenar  eminence ;  abductor  divided  into  outer  and  inner  parts,  accessory  head 
from  parts  above ;  abductor  min.  dig.  divided  into  two  or  more  slips,  or  acces- 
sory head  from  above ;  may  be  inserted  into  fifth  metacarpal,  representing  the 
m.  pisi-metacarpeus ;  there  may  also  be  the  m.  pisi-uncinatus  andm.  pisi-an- 
nularis. 

Nerves  of  Hand-muscles. — Abductor  poll.,  opponens  poll.,  outer  head  of  flexor 
brevis  poll.,  and  outer  two  lumbricales  (outer  three,  Ziemssen)  are  supplied 
by  the  median  nerve.  The  palm,  brevis,  muscles  of  little  finger,  inner  two 
lumbricales  (fourth,  Ziemssen),  all  the  interossei,  adductores  poll.,  inner  head 
of  flex.  brev.  poll.,  are  supplied  by  the  ulnar  nerve. 

Actions  of  Muscles  of  Forearm  and  Hand. — Pronation  by  pronator  teres  and 
quadratus  and  flex.  c.  rad.  slightly ;  pron.  teres  flexes  forearm  ;  can  only  pro- 
nate  wlj^en  radius  is  intact. 

Supinationhj  supinator  brevis,  biceps,  and  sup.  longus ;  the  latter  is  a,  flexor 
of  the  elhow  and  brings  the  forearm  into  mid-supination.  Radial  extensors  of 
wrist  flex  elbow ;  others  from  the  ext.  condyle  extend.  Flexion  of  wrist  by 
flex.  c.  uln.  and  rad.,  by  flexors  of  fingers,  and  palm,  longus. 

Extension  of  wrist  by  extens.  c.  uln.,  the  two  radial  extensors,  and  exten- 
sors of  fingers.  \ 

Abduction  of  wrist  by  radial  flexor  and  radial  extensors  and  extensors  of 
thumb. 

Adduction  of  wrist  by  the  flexor  and  extensor  c.  uln.    The  flex.  c.  rad.  and 


186  MUSCLES   AND   FASCIAE   OF   THE   EXTREMITIES. 

extens.  c.  uln.  act  on  the  radio-carpal  joint ;  the  flex.  c.  uln.  and  radial  exten- 
sors on  the  mid-carpal  joint. 

The  extensors  of  the  wrist  are  moderators  of  the  long  flexors  of  the  fingers ; 
the  flexors  of  the  wrist  are  moderators  of  the  extensors  of  the  fingers. 

The  dorsal  interossei  abduct  the  fingers  from  the  middle  one ;  the  palmar 
adduct ;  the  interossei  and  lumbricales  flex  the  first  phalanx  and  extend  the 
last  two  (a  movement  in  forming  the  hair-stroke  in  writing). 

Flexion  in  Fingers.  Extension  in  Fingers. 

1st  phalanx,  by  interossei  and  lumbricales.  By  extensor  communis. 

2d  phalanx,  by  flexor  sublimis.  By  interossei  and  lumbricales. 

3d  phalanx,  by  flexor  profundus.  By  interossei  and  lumbricales. 

When  we  flex  fingers  they  tend  to  approach,  due  to  lat.  ligaments  and  obliq- 
uity of  tendons. 

The  palmaris  longus  makes  tense  the  palmar  fascia,  feebly  flexes  forearm 
and  wrist ;  all  the  muscles  from  the  inner  condyle  feebly  flex  forearm. 

Palmaris  brevis  wrinkles  the  skin  over  the  hypothenar  eminence  and  pro- 
tects the  ulnar  vessels  and  nerve  from  pressure  when  a  foreign  body  is 
grasped. 

Extension  in  the  tMimh  is  in  the  plane  of  abduction  of  "the  flngers,  and  its 
abduction  is  a  movement  forward.  The  action  of  its  muscles  and  those  of  the 
little  finger  are  indicated  by  their  names :  the  flexors  of  the  first  phalanx  in 
either  case  also  extend  the  last,  as  the  interossei  would.  The  ulnar  extensor 
and  fiexor  of  the  carpus  are  moderators  of  the  thumb  extensors.  There  are 
three  flexors  of  the  wrist  (including  palmaris  long.)  and  three  extensors, 
three  flexors  of  fingers  and  three  extensors,  three  flexors  of  thumb  and  three 
extensors. 

Muscles  and  Fasciae  of  the  Lower  Extremity. 

THE  HIP  AND  THIGH. 
Describe  the  fasciae  of  hip  and  thigh. 

The  superficial  fascia  is  continuous  with  that  of  other  parts  of  the 
body.  Thick  over  gluteal  region,  passes  over  Poupart's  ligament  into 
dartos  of  scrotum  and  superficial  fascia  of  perineum.  A  deep  layer  of 
this  fascia  is  continued  across  the  saphenous  opening,  perforated  by  ves- 
sels and  lymphatics,  crihr  if  or  m  fascia. 

The  deep  fascia  ox  fascia  lata  is  a  strong  membrane  forming  a  continu- 
ous sheath  around  the  limb :  it  is  attached  above  to  back  of  sacrum  and 
coccyx,  crest  of  ilium,  Poupart's  ligament,  body  and  rami  of  pubis^^ ramus 
and  tuberosity  of  ischium,  and  lower  margin  of  great  sacro-sciatic  liga- 
ment. It  descends  on  the  glut,  medius  as  far  as  the  upper  border  of  the 
glut,  max.,  which  muscle  it  encases,  and  over  the  great  trochanter  a 
great  part  of  the  muscle  is  inserted  between  its  laj^ers.  ^  From  ihe  fore 
part  of  the  i^ptc  crest  to  the  outer  tuberosity  of  the  tibia  is  the  ilio-tihial 
hand,  which  receives  the  tensor  vag.  fem.  and  glut.  max.  insertions. 

The  fascia  is  thinnest  at  the  inner  part  of  the  thigh  over  the  adduc- 
tors, and  strengthened  on  each  side  of  the  patella  by  expansions  from 


THE   HIP  AND   THIGH.  187 

the  vasti.  Posteriorly  it  is  continuous  over  the  hamstrings  and  popUteal 
space. 

On  the  front  of  the  thigh,  below  the  inner  end  of  Poupa^t's  ligament, 
is  the  saphenous  opening^  bounded  externally  by  the  falciform  border 
(ligament  of  Burns),  more  distinctly  curved  above  and  below  as  sUp. 
and.  inf.  cornua.  The  inner  extremity  of  the  sup.  cornu  passes  to  the 
inner  side  of  the  fem.  sheath  and  to  Gimbernat's  ligament:  it  is  the 
femoi^al  ligament  (Hey). 

The  parts  external  and  internal  to  the  saphenous  opening  are  the  iliac 
and  picbic  portions:  the  iliac  is  connected  above  with  Poupart's  and  the 
deep  layer  of  superficial  fascia  (of  Scarpa),  and  internally  forms  the  fal- 
ciform margin  of  the  saphenous  opening. 

The  pubic  portion,  or  pectineal  fascia,  is  attached  above  to  the  ilio- 
pect.  line,  passes  behind  the  femoral  vessels,  closely  connected  with  the 
sheath,  and  merges  into  the  iliac  fascia  and  capsule  of  hip. 

The  fascia  lata  has  various  deep  processes :  one  is  internal  to  the  ten- 
sor vag.  fem.  on  the  surface  of  the  vastus  ext. 

There  are  ext.  and  i7it.  intermuscular  septa  inserted  into  the  linea 
aspera. 

The  femoral  vessels  are  surrounded  by  the  funnel-shaped  crural  sheath, 
made  of  transversalis  fascia  in  front  and  iliac  fascia  behind  ;  it  is  divided 
into  three  compartments — outermost  for  the  artery,  middle  one  for  the 
vein,  and  innermost  contains  a  lymphatic  gland  and  fat,  and  when  dis- 
tended by  a  femoral  hernia  is  the  crural  canal,  \  to  If  inches  (14  to  34 
mm.)  long.  The  crural  ring  (upper  opening  of  the  canal)  is  closed  by 
the  septum  crurale. 

Describe  the  muscles  of  the  hip. 

Internal  Hip-muscles. — 1.  M.  Quadratus  Lumhorum. — A  quadri- 
lateral muscle  placed  between  the  last  rib  and  pelvis.  Origin,  ilio-lum- 
bar  ligament,  crest  of  ilium  for  2  inches,  from  two,  three,  or  four  lumbar 
trans,  processes  by  "fleshy  slips  passing  up  anteriorly  (Gray  says  this  is  a 
separate  portion) ;  insertion,  inner  half  last  rib  and  upper  four  lumbar 
trans,  processes. 

Its  sheath  is  formed  behind  by  the  costo-lumbar  lig.,  and  in  front  by  part 
of  the  ilio-lumbar  lig.,  middle  and  ant.  layers  of  lumbar  fascia.  Henle  de- 
scribes its  origin  as  above  and  insertion  below.  If  the  twelfth  rib  is  lacking, 
it  goes  to  the  eleventh. 

Nerves. — Last  dorsal  and  upper  lumbar. 

Actions. — Lateral  flexor  or  both  may  extend  spine.  Draws  down  the  last 
rib,  giving  fixed  point  for  diaphragm,  and  aids  inspiration  (Quain) ;  muscle 
of  forced  expiration  (Henle).  Fixed  above,  draws  pelvis  to  one  side,  or  both 
draw  it  forward. 

2.  M.  Ilio-psoas. — It  has  a  broad  outer  head,  iliacus,  and  a  narrow 
inner  head,  psoas  magnus. 

Iliacus. —  Origin,  upper  half  of  iliac  fossa  down  as  far  as  ant.  inf. 
spine,  posteriorly  from  ala  of  sacrum  and  sacro-iliac  and  ilio-lumbar  Hga- 


188         MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

ments.  Inserted  mostly  into  tendon  of  psoas ;  outermost  fibres  pass  to 
femur  in  front  of  and  below  small  trochanter. 

Psoas  Magmus  {or  Major). — Origin,  by  five  fleshy  sUps  from  anterior 
surfaces  and  lower  borders  of  the  lumbar  trans,  proc,  and  by  a  series  of 
processes,  each  from  a  disk  and  contiguous  margins  of  two  bodies;  the 
highest  is  attached  to  the  last  dorsal  and  first  lumbar,  and  lowest  to 
fourth  and  fifth  lumbar  and  intervert.  subs,  between  them ;  fibres  also 
come  from  the  sacro-iliac  joint  and  sacrum.  These  attachments  are 
connected  with  arches  passing  over  the  middle  of  the  vertebrae.  The 
fibres  all. unite  to  a  thick,  long  muscle  running  along  the  brim  of  the 
pelvis,  passing  under  Poupart's,  and  inserted  by  a  tendon  into  the  small 
trochanter ;  separated  by  a  bursa. 

The  common  tendon  is  also  separated  from  the  capsule  of  the  hip  by 
a  bursa. 

M.  iliacus  minor,  or  ilio-capsularis :  Henle  calls  the  third  head.  Origin,  ant. 
inf.  spine ;  insertion,  lower  part  of  ant.  intertrochanteric  line  or  into  the  ilio- 
fem.  ligament. 

3.  M.  Psoas  Parvus  (or  Minor). — Placed  on  the  surface  of  psoas  niag- 
nus ;  from  bodies  of  last  dorsal  and  first  lumbar  vert,  and  disk  between  ; 
ends  in  a  flat  tendon  merged  into  the  ihac  fascia  and  inserted  into  the 
ilio-pect.  line  and  eminence.  When  present  its  origin  is  variable ;  was 
absent  on  both  sides  in  40  per  cent,  of  cases. 

External  Hip-muscles. — First  Layer. — M.  Gluteus  Maximiis. — 
A  quadrilateral,  very  coarse  muscle.  Origin^  posterior  fourth  of  iliac 
crest  and  rough  surface  between  it  and  posterior  gluteal  line,  back  of 
last  two  pieces  of  sacrum  and  first  three  of  coccyx,  great  sacro-sciatic 
lig.,  and  aponeurosis  of  erector  spin83. 

The  upper  half  and  superficial  fibres  of  lower  half  are  inserted  into 
fascia  lata  and  continued  into  the  ilio-tibial  band ;  the  deeper  portion  of 
lower  half  into  the  gluteal  ridge  on  the  upper  third  of  shaft  of  femur. 

Between  this  and  great  trochanter  is  a  multilocular  bursa  and  one  or  two 
small  ones,  another  between  it  and  vast.  ext. :  maybe  another  between  it  and 
tuber  ischii. 

Varieties. — Agitator  caudse,  from  coccyx  to  lower  border  of  muscle.  Fibres 
from  sacro-sciatic  lig.  and  sacrum  are  normally  separated  from  the  rest  by 
areolar  tissue,  giving  a  bilaminar  structure. 

Second  Layer. — M.  Gluteus  Medius. — Origin,  ilium  between  crest, 
post.,  and  middle  curved  lines,  and  from  fascia  covering  it,  and  from  a 
band  attached  to  the  ant.  sup.  spine  ;  fibres  converge  to  an  oblique  im- 
pression going  downward  and  forward  on  outer  surface  of  the  great  tro- 
chanter ;  a  small  bursa  between  bone  and  tendon.  There  may  be  a  sep- 
arate tendon  to  the  upper  part  of  the  trochanter. 

Third  Layer. — 1.  M.  Gluteus  Minimus  is  covered  by  preceding,  and 
rises  from  the  whole  surface  on  ilium  between  middle  and  inferior  curved 
lines,  and  by  a  second  head  from  the  ant.  sup.  spine ;  fibres  converge 
into  an  aponeurotic  tendon  on  the  outside  of  the  muscle,  inserted  into 


THE   HIP   AND   THIGH.  189 

an  impression  on  the  front  of  the  great  trochanter.  Tendon  is  bound 
down  by  band  of  capsule  of  joint  from  ilio-femoral  lig.  ;  bursa  between 
tendon  and  tubercle. 

May  be  divided  into  anterior  and  posterior  parts.  The  anterior  fibres,  if 
separate,  represent  the  scansorius  of  apes  (m.  invertor  femoris). 

2.  M.  Pyriformis. —  Origin^  in  pelvis  by  three  digitations  from  second, 
third,  and  fourth  pieces  of  sacrum,  between  anJ  outside  the  ant.  sacral 
foramina,  from  the  hinder  border  of  ilium  below  post,  inf  spine,  and 
from  great  sacro-sciatic  lig.  Emerges  from  pelvis  by  great  sacro-sciatic 
foramen;  inserted  vaio  upper  border  of  great  trochanter. 

May  be  divided  by  the  ext.  pop.  nerve  (high  division  of  sciatic) ;  inserted 
into  capsule  or  absent.    May  be  a  bursa  under  its  insertion. 

3.  M.  Obturator  Internus. — Origin,  deep  surface  of  obturator  mem- 
brane, except  below;  from  the  fibrous  arch,  completing  the  canal  for 
the  obturator  vessels  and  nerve ;  from  hip-bone  between  thyroid  foramen 
and  sacro- iliac  notch  up  to  iho-pect.  Une,  and  internally  between  foramen 
and  subpubic  arch  ;  from  obturator  fascia.  Emerges  by  the  small  sacro- 
sciatic  foramen,  passes  around  the  trochlear  surface  of  ischium ;  inserted 
with  the  gemelli  into  fore  part  of  inner  surface  of  great  trochanter.  It 
shows  four  or  five  tendinous  bands  on  the  surface  turned  toward  bone, 
which  receive  pinnate  fibres.  A  layer  of  cartilage  covers  the  grooves  on 
the  ischium  and  a  large  synovial  bursa.  Another  may  be  between  the 
capsule  and  tendon.  Henle  describes  the  gemelli  (gemini)  as  parts  of 
this  muscle,  calling  them  its  outer  head. 

The  gemellus  sup. ,  usually  the  smaller.  Origin,  outer  and  lower  part 
of  ischial  spine.  Gemellus  inf. — Origin,  upper  part  tuber  ischii  below 
obturator  internus;  inserted  with  obturator  int.  into  the  great  trochanter. 
They  usually  meet  at  origin  beneath  the  obturator ;  they  overlap  it  at 
the  insertion.  The  sup.  gemellus  may  be  absent  or  very  small;  inf 
gemellus  is  more  constant. 

4.  M.  Quadratus  Femoris. —  On^/m,  outer  border  tuber  ischii;  inser- 
tion, horizontally  outward  into  quadrate  tubercle  and  back  of  femur  to 
level  of  small  trochanter.  Bursa  between  it  and  small  trochanter :  it 
may.be  absent  or  replaced  by  the  gemellus  inf 

Fourth  Layer.— J/.  Obturator  Externus. — Origin,  inner  half  of 
outer  surface  of  obturator  membrane,  body  of  pubis,  rami  of  pubis  and 
ischium ;  passes  out  in  a  groove  between  acetabulum  and  tuber  ischii, 
then  up  and  backward,  close  to  lower  and  posterior  surface  of  neck  of 
femur  to  bottom  of  digital  fossa.  Sometimes  bursa  is  betAveen  it  and 
capsule. 

Nerves. — Ilio-psoas  by  second  and  third  lumbar;  those  for  iliacus  are  given 
oflT  by  ant.  crural ;  glut.  max.  by  inf.  gluteal  nerve ;  gluteus  med.  and  min. 
by  sup.  gluteal  nerve ;  obturator  int.,  gemelli,  pyriformis,  and  quadratus  fem. 
by  sacral  plexus ;  obturator  ext.  by  obturator  nerve. 


190  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

Actions  of  glutei  on  lower  limb : 

Flexion.  Extension. 

Glut,  med.,  anterior  fibres.  Glut,  maximus. 

"     min.,       "  "  "     med.,  posterior  fibres. 

"     min., 

Adduction.  Abduction. 

Glut,  med.,  anterior  fibres  |  in  sitting    Glut,  max.,  slight. 

"     min.,         "  "•  J  posture.  "     med.,  )  strong,  whole  muscle,  es- 

"     min.,  J      pecially  mid.  portion. 

Eotate  in.  Rotate  out. 

Glut,  med.,  anterior  fibres.  Glut.  max. 

*'     min.,         ''  "  "     med.,  posterior  fibres. 

"     min.,        "  " 

The  gluteus  maximus  extends  trunk  on  thigh  as  in  ascending  stairs ;  in  walk- 
ing it  is  not  used,  as  erect  position  is  maintained  by  ligaments ;  steadies  and 
supports  knee  by  ilio-tibial  band. 

The  iUo-psoas  flexes  thigh  and  rotates  out ;  flexes  body  on  thigh :  the  psoas 
bends  the  lumbar  spine  forward  and  laterally. 

Psoas  parvus  makes  tense  the  iliac  fascia. 

Pyriformis,  obturator  hit.,  and  gemelli  are  external  rotators  after  extension, 
abductors  if  thigh  is  flexed. 

Quadratus  femoris  is  an  external  rotator,  and  may  assist  adduction. 

Obturator  externus  is  an  external  rotator ;  may  flex  and  adduct. 

Describe  the  thigh-muscles. 

There  are  three  sets — anterior,  posterior,  and  internal,  with  superficial 
and  deep  layers,  the  former  passing  over  two  joints,  the  latter  over  one. 

Anterior  Group.— First  Layer.— 1.  M.  tensor  vagince  femoris 
(tensor  fasciae)  lies  in  a  groove  between  glut,  med.,  rectus,  and  sartorius. 
Origin.,  anterior  part  of  external  lip  of  iliac  crest,  notch  between  the  two 
spines,  fascia  over  gluteus  med.  ;  insertion.,  between  two  layers  of  fascia 
lata  3  or  4  inches  below  the  great  trochanter,  and  from  the  insertion 
fibres  are  prolonged  into  the  ilio-tibial  band ;  the  outer  of  the  two  lam- 
inae covers  the  muscle ;  the  deeper  is  connected  with  the  origin  of  the 
rectus. 

2.  M.  Sartorius  (tailor  muscle). —  Origin^  anterior  sup.  spine  of  ilium 
and  small  part  of  notch  below ;  insertion^  inner  surface  of  tibia  near 
tubercle,  sending  an  expansion  from  upper  border  to  capsule,  one  from 
lower  border  to  fascia  of  leg,  and  one  to  tibia  behind  the  tendons  of 
gracilis  and  semitendinosus.  It  is  oblique  at  first,  then  vertical  to  the 
knee,  and  then  curves  forward. 

Varieties. — Separate  head  from  notch,  ilio-pect.  line,  Poupart's,  pubis  close 
to  symphysis;  insertion  into  fascia  lata,  capsule  of  kuee,  or  fascia  of  leg;  an 
accessory  insertion  into  fascia  lata,  femur,  or  lig.  patellae;  tendinous  inscrip- 
tion on  muscle.  There  is  a  common  bursa  beneath  its  tendon  and  those  of 
the  gracilis  and  semitendinosus. 

Second  Layer. — M,  Quadriceps  Femoris.,  p.  n. — Largest  muscle  of 


THE    HIP   AND    THIGH.  191 

body,  four  parts  closely  united,  (a)  Rectus  femoris,  in  a  straight  line 
from  pelvis  to  patella.  Origin^  by  two  heads :  anterior  one  from  ant. 
inf.  spine,  and  posterior  from  impression  just  above  acetabulum ;  they 
join  at  an  angle  of  60°  close  below  the  acetabulum  ;  tendon  is  anterior 
above,  then  in  centre  of  muscle.  From  this  are  pinnate  fibres  ending 
in  an  inferior  tendon  covering  the  lower  two-thirds  of  the  posterior  sur- 
face of  the  belly,  and  leaving  a  median  cleft  in  the  muscle.  The  lower 
tendon  becomes  free  3  inches  above  the  patella ;  is  attached  to  the  upper 
margin  of  that  bone,  and  helps  form  the  common  tendon. 

Some  regard  the  *'  reflected  head  "  as  the  main  tendon,  and  the  "  straight 
head  "  as  the  secondary  attachment. 

(b)  The  vastus  externus  (vastus  lateralis,  p.  n. )  is  the  outer  part  of  the 
quadriceps.  Origin,  narrow  from  upper  half  of  anterior  intertrochan- 
teric line,  outer  part  of  root  of  great  trochanter,  outer  side  gluteal 
ridge,  upper  half  linea  aspera,  its  outer  lip,  from  ext.  intermusc.  septum, 
and  a  strong  aponeurosis  extending  over  the  upper  two-thirds  of  muscle. 
It  rises  in  a  succession  of  layers,  the  upper  overlapping  the  lower. 
Aponeurosis  of  insertion  occupies  the  deep  surface  of  muscle,  joins  the 
common  tendon,  and  sends  expansion  to  lat.  patellar  ligaments  and  rec- 
tus tendon. 

(c  and  d)  Vastus  internus  (vastus  medialis,  p.  n.)  and  crureus  (femora- 
lis,  p.  n. )  seem  to  form  one  mass,  but  turn  the  rectus  tendon  well  down, 
and  above  patella  is  an  interval  which  can  be  followed  up  between  the 
two  tendons  on  line  with  lower  end  of  anterior  intertrochanteric  line. 

The  vastus  internus  rises  from  a  superficial  aponeurosis  and  deeper 
fibres  from  the  spiral  line,  inner  lip  of  linea  aspera,  and  from  tendons  of 
adductor  longus  and  magnus :  they  end  in  a  deep  aponeurosis  which  en- 
ters the  common  tendon.  Its  muscular  fibres  pass  lower  than  those  of 
the  externus,  and  are  inserted  into  the  inner  margin  of  the  patella,  some 
into  the  rectus  tendon. 

Crureus,  from  upper  two-thirds  of  anterior  surface  of  femur,  outer  sur- 
face of  femur  in  front  of  and  below  vastus  ext. ,  lower  half  of  ext.  inter- 
muscular septum ;  fibres  end  in  a  superficial  aponeurosis  which  forms 
the  deepest  portion  of  the  common  tendon.  They  rise  from  a  series  of 
transverse  arches  with  intervening  bare  spaces  on  the  front  of  the  femur. 
Between  this  portion  and  the  vastus  int.  most  of  the  internal  surface  of 
the  bone  is  free. 

The  common  or  suprapateUar  tendon  is  inserted  into  the  fore  part  of 
the  upper  border  of  the  patella,  and  a  few  fibres  are  prolonged  over  its 
anterior  surface  into  the  lig.  patellae. 

Third  Layer. — M.  suhcruralis  (articularis  genu, p.  7i.)  is  the  name  of 
a  few  fibres  which  may  be  regarded  as  the  deepest  layer  of  the  crureus. 
Origin,  anterior  surface  of  femur;  insertion,  separated  by  a  fat  laj^er 
from  vasti  into  the  synovial  membrane  of  knee-joint. 

These  muscles  may  be  bilaminar. 


192  MUSCLES   AND   FASCIA   OF  THE   EXTREMITIES. 

Huntefs  canal  is  a  three-cornered  passage  in  the  middle  two-fourths  of  the 
thigh,  in  the  angle  between  the  adductor  magnus  and  longus  and  vastus  inter- 
nus.  It  is  made  a  canal  by  abridge  of  fascia,  and  contains  the  femoral  artery, 
vein,  and  internal  saphenous  nerve. 

Nerves. — Anterior  crural  for  quadriceps  and  sartorius ;  superior  gluteal  for 
tensor  vag.  fem. 

Actions. — Sartorius  flexes  hip  and  knee  with  eversion  of  thigh ;  rotates  leg 
inward. 

Quadriceps  femoris  extends  leg ;  not  necessary  for  maintenance  of  erect  atti- 
tude. 

Rectus  fem.  also  flexes  hip ;  its  posterior  head  is  tense  when  thigh  is  bent. 
Lower  fibres  of  vastus  int.  draw  patella  in. 

Tensor  vag.  fem.  rotates  in  and  abducts,  assisted  by  glut.  max. ;  counteracts 
the  glut,  max.,  which  tends  to  draw  the  ilio-tibial  band  backward. 

Posterior  Group,  or  Hamstrings. — 1.  M.  Biceps  Femoris. — 
Origin^  long  head  by  a  tendon  common  to  it  and  semitendinosus  from 
inner  impression  on  lower  part  of  ischial  tuberosity,  and  from  sacro-sci- 
atic  lig.  ;  sJiort  head  from  middle  third  of  outer  lip  of  linea  aspera  and 
ext.  intermuscular  septum ;  fibres  from  both  heads  end  in  a  tendon  in- 
serted into  the  upper  and  outer  part  of  head  of  fibula  by  two  portions 
embracing  the  ext.  lat.  lig.  ;  some  fibres  pass  forward  and  inward  to  the 
tuberosity  of  the  tibia  and  to  fascia  of  leg. 

A  bursa  is  almost  constantly  between  the  tendon  and  ext.  lat.  lig.,  or  an- 
other between  the  long  head  and  semimembranosus.  Short  head  absent ;  ad- 
ditional one  from  various  sources.  A  slip  from  long-  head  to  gastrocnemius 
or  to  tendo  Achillis. 

2.  M.  Semitendinosits.  —From  tuberosity  of  ischium  and  tendon  com- 
mon to  it  and  biceps  for  3  inches.  Terminates  in  lower  third  of  thigh 
in  a  long,  slender  tendon,  and  curves  forward  in  an  expanded  form  into 
upper  part  of  inner  surface  of  tibia  or  ant.  crest  of  tibia,  and  sends  a 
process  to  fascia  of  leg.  It  is  below  the  gracilis  tendon,  covered  by  the 
sartorius,  and  a  bursa  separates  the  three  from  the  int.  lat.  lig.  It  has 
a  thin,  oblique  intersection  in  the  middle  of  its  belly. 

3.  M.  Semimembranosus. —  Origin^  tuber  ischii  above  and  outside  the 
tendon  of  biceps  and  semitendinosus,  and  its  tendon  is  grooved  poste- 
riorly for  the  common  tendon  of  those  two  muscles.  Tendon  of  origin 
is  on  outer  side  of  muscle  for  three-fourths  the  length  of  thigh ;  ten- 
don of  insertion,  on  opposite  side  of  muscle,  and  turns  forward  and  is 
inserted  by  four  parts  (1)  into  horizontal  groove  on  back  of  inner  tube- 
rosity of  tibia ;  (2)  expansion  is  sent  up  and  in  as  the  posterior  oblique 
lig.  of  the  knee-joint;  (3)  down  to  the  fascia  over  the  popliteus  muscle; 
(4)  to  form  the  short  int.  lat.  lig.  of  .the  knee-joint. 

The  hamstring  muscles  descend  mostly  in  contact  with  each  other  and  bound 
down  by  the  fascia  lata ;  inferiorly  they  diverge  the  biceps  to  the  outer  side, 
semimembranosus  and  semitend.  to  the  inner  side,  forming  the  upper  borders 
of  the  popliteal  space,  the  inferior  margins  of  which  are  formed  by  the  heads 
of  the  gastrocnemius. 

Varieties.— GvQd,t  reduction  in  size  of  semimemb.  or  absence. 


THE   HIP  AND   THIGH.  193 

M.  iscMo-aponeuroticus  is  a  muscular  slip  from  one  or  other  hamstring  to 
the  fascia  of  the  back  of  the  leg. 

Nerves. — Great  sciatic,  from  its  int.  popliteal  division,  except  that  to  the 
short  head  of  the  biceps,  which  is  from  the  ext.  popliteal  division. 

Actions. — Flex  knee,  and  then  can  rotate  tibia  and  drag  it  back  under 
femur;  biceps  outward,  other  two  inward.  Powerful  extensors  of  hip,  and 
limit  flexion  of  that  joint  when  knee  is  extended. 

Internal  Group.— First  Layer.— 1.  i¥.  Pectiiims— Origin^  ilio- 
pect.  line  from  ilio-pect.  eminence  and  spine  of  pubis,  and  slightly  from 
bone  in  front  of  this,  and  from  fascia  over  the  muscle ;  ifisertion,  femur 
behind  small  trochanter  and  upper  part  of  Hue  passing  to  the  trochanter. 
At  origin  surfaces  are  frontal,  at  insertion  are  sagittal. 

2.  M.  Adductor  Longus  (add.  fem.  longus). — Flat  and  triangular,  in- 
ternal to  the  pectineus,  on  same  plane.  Origin.,  short  tendon  from  body 
of  pubis  below  crest  and  near  angle ;  insertion.,  inner  lip  of  linea  aspera, 
united  to  vastus  int.  in  front  and  adductor  mag.  behind. 

3.  M.  Gracilis^  or  adductor  gracilis.  —  Origin.,  inner  margin  pubic  bone 
and  whole  length  of  its  inferior  ramus,  thin  and  flat,  then  narrow  and 
thicker.  A  round  tendon  in  lower  third  of  thigh,  curving  forward  be- 
low, inserted  into  inner  side  of  tibia  just  above  semitend.  and  covered  by 
sartorius. 

Second  Layer. — M.  Adductor  Brevis. — Origin^  body  and  inferior 
ramus  of  pubis  below  adductor  longus,  between  gracilis  and  obturator 
ext. ;  insertion.,  into  the  whole  of  the  line  from  small  trochanter  to  linea 
aspera  behind  the  pectineus.  It  lies  between  the  adductor  mag.  and 
longus. 

Third  Layer. — 1.  M,  Adductor  Fem.  Minimus. — This  is  what  is  de- 
scribed with  the  add.  magnus,  usually  as  its  anterior  and  superior  por- 
tion. Origin^  body  of  pubis  and  ischio-pubic  rami ;  insertion.,  femur,  in 
a  Hue  from  quad.  fem.  to  upper  end  of  linea  aspera,  and  a  short  distance 
along  it. 

2.  31.  Adductor  Magnus. — Origin.,  ischial  ramus  internal  to  the  above 
muscle  and  tuber  ischii ;  fibres  pass  in  two  layers,  one  to  the  inner  lip 
of  linea  aspera,  and  other  on  inner  side  of  opening  for  femoral  vessels  by 
a  distinct  rounded  tendon  to  the  adductor  tubercle  on  the  inner  condyle 
of  the  femur.  The  femoral  attachment  is  interrupted  by  three  or  four 
tendinous  arches  for  the  perforating  arteries. 

Varieties. — Pectineus  may  be  divided  into  two  parts,  supplied  by  different 
nerves,  natural  in  many  animals.     May  be  inserted  into  capsule  of  hip. 

Add.  longus  may  extend  to  knee,  inseparable  from  add.  magnus. 

Add.  brevis  may  consist  of  two  or  three  parts. 

Add.  magnus,  condylar  part  may  be  distinct ;  usual  in  apes. 

Nerves. — Adductors  by  obturator  nerve,  but  add.  magnus  also  by  great  sci- 
atic ;  pectineus  jegularly  by  a  branch  from  ant.  crural,  an  offset  from  the 
obturator  and  accessory  obt.  nerve,  only  occasionally  present. 

Actions. — All  adduct  the  thigh.  Pectineus,  add.  longus,  and  brevis  flex  the 
hip,  while  part  of  the  add.  magnus  from  the  ischial  tuberosity  to  condyle 
13— A. 


194  MUgCLES   AND  FASCIJE   OF   THE   EXTREMITIES. 

may  extend  the  thigh  and  rotate  in.     Gracilis  flexes  knee  and  rotates  leg  in- 
ward.   Adductors  and  opponents,  the  gluteals,  balance  the  body  in  walking. 

What  are  the  internal  rotators  of  the  thigh  ? 

(1)  Anterior  fibres  of  glut.  med.  (2)  and  minimus;  (3)  tensor  vaginae  femo- 
ris ;  and  some  say  (4),  the  condylar  part  of  the  add.  magnus. 

THE  LEG-. 
Describe  the  muscles  and  fasciae  of  the  leg. 

Three  groups  as  in  the  forearm,  only  the  extensors  are  on  the  anterior 
side  and  flexors  posterior.  The  number  of  muscles  passing  over  two 
joints  is  less  in  the  leg ;  no  muscle  on  the  anterior  and  fibular  side  springs 
from  above  the  knee. 

Fascise. — ^The  aponeurosis  of  the  leg  is  not  continued  over  the  subcu- 
taneous surface  of  the  bones,  but  intimately  blended  with  the  periosteum. 
It  is  dense  at  the  upper  and  front  part.  Posteriorly  it  is  continuous  with 
fascia  lata,  and  receives  accessions  from  the  biceps,  sartorius,  gracilis, 
and  semitendinosus  and  membranosus  tendons.  Over  the  popliteal  space 
are  transverse  fibres.  It  gives  off  intermuscular  septa.  In  front  of  and 
on  the  sides  of  the  ankle  the  apon.  is  strengthened  by  strong  bands, 
forming  the  annular  ligaments. 

The  anterior  annular  ligament  includes  two  structures — an  upper  band, 
lig.  annulare^  p.  n. ,  transversely  between  the  anterior  borders  of  the 
fibula  and  tibia.  The  tibialis  anticus  tendon  alone  has  a  synovial  sheath 
under  it.  The  lower  band,  lig.  crudatum^  p.  n.,  resembles  the  letter  Y 
placed  on  its  side,  one  arm  being  external  and  two  internal.  The  outer 
portion  springs  from  the  hollow  of  the  os  calcis,  forming  a  strong  loop, 
''''  fundi  form  ligament  of  Retzius.,^^  surrounding  the  peroneus  tertius  and 
extensor  longus  digit.  The  straight  and  most  constant  internal  band 
passes  to  the  internal  malleolus  over  the  extensor  pollicis  (hallicis),  and 
practically  beneath  the  tibialis  ant.  tendon  ;  the  lower  band  crosses  both 
those  tendons,  and  becomes  continuous  with  plantar  fascia  on  the  inner 
side  of  the  sole. 

There  are  three  synovial  sheaths  in  all :  a  common  one  for  the  pero- 
neus tertius  and  extensor  longus,  one  for  the  extens.  poll. ,  and  one  for 
the  tib.  anticus ;  may  be  a  bursa  between  the  fundiform  lig.  and  neck 
of  astragalus. 

Int.  annular  lig.  [lig.  laciniatum^  p.  n.)  covers  the  flexor  tendons, 
completing  canals;  it  is  attached  to  the  inner  malleolus  and  posteriorly 
to  the  inner  side  of  the  os  calcis. 

The  ext.  ann.  lig.  [retinaculum  peronceorum  superius^  p.  n.)  forms 
sheaths  for  the  long  and  short  peroneal  tendons,  passing  from  the  outer 
malleolus  to  the  os  calcis.  May  be  subcutaneous  bursae  over  the  mal- 
leoli and  over  the  lower  end  of  the  tendo  Achillis. 

Anterior  Group. — 1.  M.  Tibialis  Anticus  ("chain  muscle  "). — Ori- 
gin^ ext.  tuberosity  of  tibia,  upper  half  outer  surface  of  that  bone,  and 
adjacent  inteross.  memb.,  fascia  of  leg,  and  inter  muse,  septum;  insertion., 


THE   LEG.  195 

oval  mark  on  inner  and  lower  part  of  int.  cuneiform  and  first  metatarsal, 
dividing  into  two  slips.     A  small  bursa  may  be  under  it  near  insertion. 

A  part  inserted  into  astragalus,  a  slip  to  head  first  metatarsal  or  first 
phalanx. 

M.  tibio- fascialis  anticus^  from  lower  part  of  tibia  to  ann.  lig.  and  deep  fascia. 

2.  M.  Extensor  Longus  or  Froprius  Hallicis.'^ — Origin^  middle  two- 
fourths  of  narrow  anterior  surface  of  fibula  and  contiguous  portion  of  in- 
terosseous membrane ;  insertion^  base  of  terminal  phalanx  of  great  toe. 
It  spreads  in  an  expansion  on  each  side  over  the  metatarso-phal.  articu- 
lation, and  almost  always  sends  a  slip  to  base  of  first  phalanx. 

Extensor  ossis  metatarsi  hallicis  is  sometimes  found  as  a  slip  from  some  sur- 
rounding muscle. 

M.  extens.  long,  primi.  internod.  hall,  is  represented  by  the  offshoot  from  the 
extensor  proprius. 

3.  31.  Extensor  Longus  Digitorwn  Pedis. —  Origin^  ext.  tuberosity 
of  tibia,  head  and  upper  two-thirds  of  ant.  surface  of  fibula,  very  largely 
from  septa  and  fascia.  Tendon  divides  into  four  slips  for  the  four  outer 
toes.  Ihey  are  continued  into  expansions  which  are  joined  on  the  first 
phalanx  by  processes  from  the  interossei  and  lumbricales.  They  divide 
into  three  parts — the  middle  inserted  into  middle  phalanx ;  the  lateral 
parts  unite,  and  are  inserted  into  the  base  of  the  terminal  phalanx  as  in 
case  of  extensors  of  fingers. 

Tendons  to  second  and  fifth  toes  may  be  doubled ;  extra  slips  from  one  or 
more  tendons  to  metatarsal  bones,  to  short  extensor,  or  to  interossei ;  a  slip 
to  great  toe.    Slip  for  little  toe  may  be  separable  to  origin. 

4.  M.  Peroneus  Tertius. — Origin^  below  extensor  longus  dig.,  and 
united  with  it ;  lower  third  or  more  of  ant.  surface  of  fibula,  from  inter- 
oss.  membrane,  from  septum  between  it  and  per.  brevis ;  insertion.,  upper 
surface  of  base  of  fifth  metatarsal,  sometimes  fourth.  This  muscle  is 
peculiar  to  man. 

Nerves. — All  by  the  ant.  tibial  nerve. 

Fibular  Muscles. — I.  M.  Peroneus  Longus. —  Origin,  few  fibres 
from  outer  tuberosity  of  tibia,  head  and  upper  two-thirds  of  ext.  surface 
of  fibula,  fascia  of  leg,  and  septa  on  each  side.     It  has  an  anterior  and  a 

Eosterior  head  with  muse. -cut.  nerve  between.  Tendon  begins  in  lower 
alf  of  leg,  passes  behind  ext.  malleolus ;  then  forward  on  outer  side  of 
OS  calcis,  winds  round  tuberosity  of  cuboid,  and  enters  its  groove,  crosses 
the  sole  obliquely,  and  is  inserted  into  outer  side  of  tuberosity  of  first 
metatarsal,  and  slightly  into  internal  cuneiform :  a  frequent  ofiset  to 
base  of  second  metatarsal  and  first  dorsal  interosseous. 

Both  peroneal  tendons  are  in  the  same  sheath  under  the  ann.  lig.,  but  on  the 
OS  calcis  each  has  its  own  sheath,  separated  by  the  peroneal  spine,  when  it  ex- 

*  Allex  or  hallex,  genitive  hallicis,  thumb  or  great  toe — there  is  no  word  hah 
lux  to  form  the  genitive  hallucis. 


196  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

ists,  and  a  fibrous  septum.    A  single  synovial  sac  sends  two  processes  down 
into  the  special  sheaths. 

A  second  synovial  membrane  is  in  the  cuboid  groove.  A  sesamoid  fibro-car- 
tilage  or  bone  is  on  the  tendon,  playing  over  the  cuboid  tuberosity.  The 
special  fascia  binding  down  the  peroneal  tendons  is  the  retinaculum  peronse- 
orum  inferius,  p.  n. 

2.  3L  Peroneus  Brevis. —  Origin^  lower  two-thirds  ext.  surface  of 
fibula,  overlapping  the  peroneus  long.,  from  septa  and  a  flat  tendon 
on  the  surface  turned  toward  the  bone  ;  insertion^  tuberosity  at  base  of 
fifth  metatarsal,  sending  a  small  slip  to  the  outer  edge  of  extensor  of  lit- 
tle toe  or  fore  part  of  the  metatarsal  bone. 

Varieties. — Fusion  is  rare.  Slip  from  per.  long,  to  base  of  third,  fourth,  or 
fifth  metatarsal  or  to  adduct.  hall. 

M.  peroneus  access,  arises  from  fibula  between  brevis  and  longus,  and  joins  the 
latter  in  sole  of  foot. 

M.  peroneus  quint,  digiti,  from  lower  fourth  of  fibula  under  per.  brevis,  in- 
serted into  extensor  apon.  of  little  toe,  commonly  represented  by  slip  of  per. 
brevis.     Occurs  normally  in  many  animals. 

M.  peroneus  quartus  (13  percent.),  from  back  of  fibula  between  per.  brevis 
and  flexor  hall.,  inserted  into  peroneal  spine  (peroneo-calcaneus)  or  tuberosity 
of  cuboid  (peroneo-cuboideus). 

Nerves. — Musculo-cut.  branch  of  ext.  popliteal  nerve. 

Posterior  G-roup. — Superficial  Muscles. — 1.  Mm.  Gastrocnemius 
and  Soleu^  (m.  triceps  surae). — Gastrocnemius  has  two  large  heads  from 
the  femur,  terminating  in  the  middle  of  the  leg  in  a  common  tendon. 
Outer  head  from  depression  on  outer  side  ext.  condyle  above  tuberosity, 
and  from  post,  surface  of  femur  just  above  that  condyle.  Inner  head 
from  upper  part  of  int.  condyle  behind  adductor  tubercle,  and  lower  end 
of  supracondylar  ridge.  The  two  heads  enlarge,  and  soon  meet,  do  not 
join ;  separated  superficially  by  a  groove  and  deeply  by  a  thin  band. 

The  inf.  tendon  is  broad  and  aponeurotic,  and  on  the  deep  surface. 

The  lower  edge  of  each  muscular  part  is  convex  downward :  the  inner 
head  is  the  broader  and  thicker,  and  descends  the  lower.  A  bursa  is 
between  it  and  the  semimembranosus,  and  another  between  it  and  the 
femur. 

Outer  head  may  develop  a  sesamoid  fibro- cartilage  or  bone  over  the 
condj^le  of  the  femur. 

Soleits. —  Origin,  externally  from  post,  surface  of  head  and  upper  third 
of  shaft  of  fibula ;  internally,  oblique  line  and  inner  border  of  tibia  to 
its  middle,  and  from  a  tendinous  arch  over  popliteal  vessels  and  nerve  ; 
fibres  rise  to  a  large  extent  from  two  tendinous  laminas  which  descend 
in  the  muscle,  one  from  the  fibula  and  one  from  the  tibia.  Fibres  from 
the  ant.  surfaces  of  these  laminae  converge  to  a  median  septum ;  fibres 
from  their  post,  surfaces  pass  down  and  back  to  an  aponeurosis  covering 
the  back  surface  of  the  muscle.  The  tendon  of  insertion  is  prolonged 
from  this  aponeurosis,  joined  by  t!ie  median  septum.     Muscular  fibres 


THE   LEG.  197 

are  continued  down  on  the  deep  surface  of  the  tendo  Achillis  near  to  the 
heel.     The  tibial  head  is  almost  pecuhar  to  man. 

Tendo  Achillis^  broad  at  first,  contracts  to  within  li  inches  of  heel, 
then  expands,  and  is  inserted  into  middle  of  post,  surface  of  tuberosity 
of  OS  calciSj  with  a  bursa  between,  having  all  the  characters  of  a  syno- 
vial membrane,  with  vascular  and  fatty  synovial  tufts. 

2.  M.  Plantaris. — Origin,  femur  above  external  condyle  and  from 
post.  lig.  of  knee-joint.  Muscular  belly  3  to  4  inches  long,  and  the  long, 
slender  tendon  turns  in  between  gastrocnemius  and  soleus  to  inner  border 
of  tendo  Achillis,  and  inserted  by  its  side  into  calcaneum. 

May  join  tendo  Achillis,  end  in  fascia  of  leg  or  int.  ann.  lig.,  or  be  enclosed 
in  the  tendo  Achillis.  Absent  in  7.5  per  cent.  It  is  the  remains  of  a  super- 
ficial flexor  of  the  digits,  like  the  palmaris  longus. 

3.  M.  Popliteus. —  Origin,  round  tendon,  1  inch  long,  from  groove  on 
outer  surface  of  ext.  condyle  of  femur,  within  capsule  of  joint,  in  contact 
with  semilunar  cartilage,  and  by  muscular  fibres  from  lig.  popl.  arcuatum. 
Fibres  pass  down  and  are  inserted  into  triangular  surface  of  tibia  above 
oblique  Hne,  and  into  aponeurosis  over  the  muscle.^  The  tendon  is  in  the 
groove  on  the  femur  only  in  full  flexion.  Henle  gives  origin  below  and 
insertion  above. 

M.  popliteus  minor  (rare),  from  femur,  inner  side  of  plantaris,  inserted  into 
post.  lig.  of  knee. 

M.  peroneo-tibialis  (1  in  7),  from  inner  side  of  head  of  fibula  to  upper  end  of 
oblique  line  of  tibia  beneath  popliteus  ;  constant  in  apes. 

Beep  Muscles. — 1.  M.  Flexor  Longus  Digitorum  Pedis  (perforans). 
—  Origin,  inner  portion  post,  surface  tibia  for  middle  two-fourths  of  length, 
from  apon.  over  tibialis  post. ,  from  inner  border  of  fibula.  Descends  be- 
hind int.  malleolus,  passes  forward  and  obliquely  outward,  having  crossed 
the  tibialis  post,  tendon  in  tKe  leg,  and  now  crossing  that  of  the  flex, 
longus  hall. ,  in  each  case  superficially.  It  divides  into  four  parts  for 
terminal  phalanges  of  the  four  lesser  toes.  The  whole  arrangement  with 
vinculae  access,  etc.  is  as  for  the  fingers. 

•M.  flexor  access,  long,  digitortim  rises  from  fibula  or  tibia  or  deep  fascia,  and 
passes  beneath  int.  ann.  lig.  and  joins  the  long  flexor  or  the  accessorius. 

2.  M.  Tibialis  Posticus,  beneath  the  two  long  flexors.  Origin,  post, 
surface  of  inteross.  membrane,  outer  part  of  posterior  surface  of  tibia  to 
middle  of  bone,  whole  inner  surface  of  fibula,  and  from  aponeurosis 
over  it.  Tendon  along  inner  border  of  muscle,  free  at  level  of  lower 
tibio-fib.  articulation,  passes  behind  inner  malleolus ;  inserted  into  tube- 
rosity of  scaphoid,  with  offsets  to  the  three  cuneiform,  to  cuboid,  bases 
of  second,  third,  and  fourth  metatarsal,  and  to  trans,  tarsal  lig.  and  abd. 
hall,  tendon,  and  sends  a  thin  process  back  to  the  sustentaculum  tali. 

Varieties  few.  Tibialis  secundus,  or  tensor  of  capsule  of  anJcle-joint,  from  lower 
half  outer  surface  of  tibia,  below  flex,  digitorum,  to  capsule  of  ankle  or  ann. 
lig.  between  tibia  and  fibula. 


198  MUSCLES   AND   FASCIA   OF   THE   EXTREMITIES. 

3.  M.  Flex.  Longm  Hall — Origin,  lower  two-thirds  post,  surface 
fibula,  septum  between  it  and  peronei;  apon.  common  to  it  and  flex, 
longus  dig.  Tendon  at  post,  surface  of  muscle  traverses  groove  on  back 
of  astragalus  and  under  surface  of  sustentaculum,  gives  slip  to  flex.  long, 
digitorum  in  sole  of  foot,  and  proceeds  to  the  base  of  terminal  phal.  of 
great  toe. 

Nearly  always  a  slip  from  flexor  hall,  to  flex  digit.,  and  (1  in  5)  another 
from  flex.  dig.  to  flex.  hall. 

Slip  from  flex.  hall,  passes  to  second  and  third  toes,  52  per  cent. ;  to  second 
only^  28  per  cent. ;  to  second,  third,  and  fourth,  19  per  cent.,  or  rarely  to  all 
four. 

M.  peroneo-calcaneus  internus  (rare),  from  back  of  fibula, 'passes  over  susten- 
taculum tali  to  OS  calcis. 

Nerves. — Gastrocnemius,  plantaris,  and  popliteus  by  int.  popliteal  n.  Soleus 
by  int.  popliteal  and  post,  tibial.  Flex.  long,  digit.,  flex.  long,  hallicis,  and 
tibialis  post,  by  post-tibial  nerve. 

THE  FOOT. 
Describe  the  muscles  and  fasciae  of  the  foot. 

Fascia  of  dorsum  is  a  thin  layer  oyer  the  extensor  tendons,  with  deeper 
layers  over  the  short  extensors  and  interossei. 

Fascia  of  sole  (superficial)  forms  a  thick  cushion  of  fatty  lobules  bound 
down  by  bands  passing  vertically  from  skin  to  deep  fascia.  Small  bursas 
over  heel  and  first  and  fifth  metacarpals. 

Deep  Fascia  of  Sole. — Plantar  fascia^  central  and  two  lateral  portions. 
The  inner  is  thin  and  loose,  covers  the  abductor  hall. ,  and  is  continuous 
with  dorsal  fascia  and  int.  ann.  lig.  Outer  part  covers  abductor  min. 
dig.,  and  forms  a  thick  band,  especially. between  outer  tubercle  of  os 
calcis  and  tuberosity  of  fifth  metatarsal,  continuous  with  dorsal  fascia, 
and  sends  a  prolongation  forward  over  short  flexors  of  little  toe. 

Central  portion  has  dense  white,  glistening  fibres,  from  inner  tubercle 
of  OS  calcis  to  roots  of  toes ;  divides  into  five  processes  in  front.  Thin 
trans,  fibres  cover  the  lumbricals  and  digital  nerves.  Identical  arrange- 
ment as  in  palmar  fascia :  fibres  to  digital  sheaths,  superficial  trans,  lig. , 
and  skin,  and  deep  processes,  to  the  trans,  metatarsal  lig. 

Two  intermuscular  septa  are  between  the  middle  and  lateral  portions, 
giving  partial  origin  to  muscles. 

Superficial  trans,  lig.  of  toes  is  in  folds  of  skin  at  interdigital  clefts, 
connected  to  tendon-sheatlfis  beneath.     Connects  all  five  digits. 

Muscles  of  Dorsum  of  Foot. 

1.  M.  Extensor  Brevis  Digitorum  Pedis. — From  fore  part  and  upper 
and  outer  surface  of  os  calcis,  in  front  of  groove  for  peroneus  brevis 
tendon,  and  from  ant.  lig.  of  ankle.  The  tendon  has  several  vertical 
leaflets  from  which  muscular  fibres  rise,  dividing  into  three  bellies  which 


THE   FOOT.  199 

unite  with  the  outer  border  of  the  long  extens.  for  the  second,  third,  and 
fourth  toes. 

2.  M.  Extensor  Hallicis  Brevis  (often  described  with  the  above). — 
Origin^  two  heads,  outer  from  upper  surface  os  calcis  close  by  ant.  edge, 
and  connected  with  the  extensor  brevis  digit.  ;  inner  head  from  lowest 
arm  of  ann.  hg.  Tendon  is  free  at  tarso-metatarsal  joint,  passes  under 
the  tendon  of  the  extensor  long.  hall. ,  and  is  expanded  and  fastened  to 
dorsum  of  first  phalanx. 

Access,  slips  from  different  bones  of  tarsus  to  tendon  for  second  toe,  or  one 
from  cuboid  to  third.  Number  of  tendons  vary ;  reduced  to  two,  one  doubled, 
or  slip  to  little  toe.  A  slip  ending  in  a  metatarso-phal.  articulation  or  dorsal 
interos.  muscle  is  rather  common,  especially  between  the  great  and  second  toe 
bellies.  Deep  slips,  forming  a  transition  to  dorsal  interossei,  may  occur ;  may 
be  a  bursa  over  the  second  and  third  metatarsal  bases. 

Muscles  of  the  Sole. 

None  corresponding  to  the  palmaris  brevis :  three  groups  as  in  the 
hand,  middle  group  richer  than  that  of  hand.  Great  toe  poorer  than 
the  thumb  group.     Little  toe  group,  like  number  and  arrangement. 

In  the  Middle. — 1.  M.  Flexor  Brevis  Digitorinn  (perforatus). — 
Origin,  inner  tubercle  of  os  calcis,  plantar  fascia,  septa,  and  calc.  cuboid 
lig.  Terminates  in  four  slender  tendons^  inserted  into  sides  of  second 
phalanges  of  four  outer  toes;  each  divides  and  gives  passage  to  the 
long  flexor,  as  does  the  flex.  subl.  of  the  hand. 

Muscle  may  pass  to  all  toes.  The  tendon  to  the  little  toe  is  always  smaller 
than  the  others,  and  wanting  in  23  per  cent. ;  may  be  replaced  (5  per  cent.) 
by  a  small  muscle  from  the  long  flexor  or  flexor  access. ;  origin  of  slip  to  fourth 
toe  may  be  transferred  to  the  long  flexor.  This  is  the  rule  for  the  outer  toes 
of  apes. 

2.  Flexor  Accessorius  (m.  quadratus  plantae,  p.  n.).— Henle  calls  it 
the  "  plantar  head  of  the  flexor  long,  digit."  ^  Flat  quadrilateral  muscle. 
Origin,  two  heads,  internal  and  larger  from  inner  surface  of  os  calcis ; 
external,  narrow  and  tendinous,  from  outer  surface  os  calcis  and  long 
plantar  lig. ;  insertion,  ext.  border  and  upper  surface  of  flex.  long,  digit, 
tendon. 

Offsets  can  be  traced  to  the  second,  third,  and  fourth  toes,  not  always  to  the 
fifth.    Muscle  may  end  in  flex.  hall,  tendon.    May  be  absent. 

3.  Mm.  Lumbricales. — Four  in  number.  Origin,  at  points  of  division 
of  flex.  long,  digit,  tendon,  each  attached  to  two  tendons,  except  the 
most  internal  one ;  they  pass  to  inner  side  of  four  outer  toes,  inserted 
into  bases  of  first  phalanges  (Henle). 

One  or  more  absent ;  doubling  of  third  and  fourth ;  Insertion  into  extensor 
tendons.     Bursse  between  tendons  and  bases  of  first  phalanges. 

Muscles  of  Great  Toe-side.— ].  M.  Abductor  Rallicis.— Origin, 
inner  tubercle  os  calcis,  int.  ann.  lig.,  septum,  plantar  fascia;  insertion^ 


200  MUSCLES   AND   FASCIA   OF  THE   EXTREMITIES. 

inner  border  of  base  first  phalanx  great  toe,  inner  sesamoid  bone,  and 
tendon  of  extens.  long.  hall.  Slip  to  first  phalanx  second  toe.  May 
have  a  second  head  from  scaphoid. 

2.  M.  Flexor  Brevis  Hallicis. — Origin^  flat  process  from  cuboid  inner 
border,  from  slip  of  tibialis  post,  tendon  to  the  two  outer  cuneiform 
bones,  from  sheath  flex.  long,  digit. ;  inserted  by  two  heads  into  inner 
and  outer  borders  of  base  of  first  phalanx,  in  connection  with  abductor 
hall,  and  adductors.     Sesamoid  bone  in  each  head. 

Origin  from  os  calcis  or  long  plantar  lig.  Sends  slip  to  second  toe,  first  phal. 
Inner  head  regarded  by  some  as  belonging  to  abductor. 

3.  M.  Adductor  Hallicu  has  two  heads  as  in  hand,  an  oblique  and 
transverse,  only  more  separated. 

Caput  Ohliquum^  p.  n. —  Origin^  tarsal  extremities  of  third  and  fourth 
metatarsals,  sheath  of  peroneus  long.,  calc. -cuboid  lig.,  and  third  cunei- 
form ;  insertion^  outer  side  of  base  of  first  phal.  of  great  toe,  somewhat 
above  the  tendon  of  the  peroneus  long. 

Caput  transversum^  transversus  pedis ^  is  covered  by  flexor  tendons. 
Origin,  inf  tarso-metatarsal  ligaments  of  three  outer  toes  and  trans, 
metatarsal  lig. ;  inserted  with  the  oblique  head  and  flexor  brevis  into 
first  phalanx  of  great  toe  and  extensor  tendon. 

In  the  foetus  the  muscle  is  close  to  the  oblique  head  at  bases  of  metatarsals ; 
it  subsequently  travels  forward  along  interosseous  fascia.  Opponens  hall. 
into  metatarsal  of  great  toe  is  sometimes  found. 

Muscles  of  Little  Toe-side.— 1.  M.  Abductor  Min.  Dig.-^ 
Origin,  both  tubercles  of  os  calcis,  ext.  septum,  band  of  plantar  fascia 
between  external  tubercle  and  base  of  fifth  metatarsal ;  inserted  into  base 
fifth  metatarsal  and  outer  side  base  first  phal.  little  toe.  The  tendon 
usually  receives  muscle-fibres  from  base  fifth  metatarsal. 

M.  abductor  oss.  metatarsi  quinti,  18  per  cent,  from  ext.  tubercle  of  os  calcis 
to  tuberosity  of  fifth  metatarsal. 

2.  M.  Flexor  Brevis  Min.  Dig. — Origin,  base  of  fifth  metatarsal,  and 
calc. -cuboid  lig.,  sheath  of  peroneus  long. ;  insertion,  base  and  ext.  bor- 
der first  phalanx  little  toe ;  deeper  fibres  generally  end  on  anterior  half 
of  fifth  metatarsal. 

3.  M.  opponens  min.  dig.  is  occasionally  (3.5  per  cent.)  separate  from  the 
flex,  brevis  min.  dig.,  especially  at  its  origin.  It  better  be  considered  the 
inner  belly  of  the  flex,  brevis,  attached  to  the  metatarsal  bone. 

Mm.  interosset,  as  in  the  hand,  are  seven  in  number,  four  dorsal  and 
three  plantar.  The  dorsal  project  downward  as  low  as  the  plantar,  and 
alternate  with  them.  Only  one  muscle  in  the  first  space,  two  in  the 
others.     The  second  toe  is  their  centre  of  insertion. 

Each  dorsal  interosseous  has  two  heads  and  a  central  tendon,  which  is 
inserted  partly  into  the  base  of  the  first  phalanx  and  into  extensor  apo- 
neurosis.   The  first  two  are  inserted,  one  on  either  side  of  the  second  toe, 


THE   FOOT.  201 

tlie  third  and  fourth  into  the  outer  sides  of  the  third  and  fourth.  Inner 
head  of  first  is  small,  and  rises  from  first  metatarsal  and  int.  cuneiform ; 
the  third  and  fourth  receive  fibres  from  sheath  of  peroneus  long. 

Plantar  interossei^  from  inner  and  under  surface  of  third,  fourth,  and 
fifth  metatarsals,  one-headed,  and  from  sheath  of  peroneus  long.  In- 
serted to  inner  sides  first  phalanges  of  third,  fourth,  and  fifth  and  ex- 
. tensor  tendons  of  toes. 

In  the  foetus  the  dorsal  interossei  are  on  the  plantar  aspect,  and  have  a  sin- 
gle origin,  corresponding  to  the  outer  head  of  the  fully-formed  muscle.  As 
the  metatarsals  become  separated  they  pass  more  to  the  dorsum  and  acquire 
another  head. 

Nerves. — Extensor  brevis  by  ant.  tibial.  Flexor  brev.  digit.,  abductor  and 
flex.  brev.  hall.,  and  innermost  lumbricalis  by  int.  plantar ;  all  the  others  by 
ext.  plantar. 

Actions. — Popliteus  flexes  knee  and  rotates  leg  in,  pulls  on  capsule  of  joint, 
and  keeps  poplit.  bursa  open.  The  dorsum  of  the  foot  and  ant.  surface  of  leg 
is  the  extensor  surface  ;  the  opposite  side  is  the  flexor  surface,  so  that  raising 
the  foot  on  the  front  of  the  leg  is  really  extension,  and  depressing  it  is  flex- 
ion :  it  is  customary  to  apply  reverse  terms  to  these  acts. 

Gastrocnemius  flexes  knee,  extends  ankle,  combines  with  soleus  and  lifts 
heel  or  raises  body  on  toes. 

Tib.  ant.  and  peroneus  tert.  flex  an*kle ;  the  former  rotates  in,  adducts,  raises 
first  metatarsal  bone. 

Tib.  post.,  peroneus  long,  and  brevis  are  extensors.  Tib.  post,  and  flexors  of 
toes  rotate  foot  in.     The  three  peronei  and  extensors  of  toes  rotate  out. 

Peroneus  long,  strengthens  trans,  arch,  lifts  outer  border  of  foot  in  walking, 
extends  foot,  depresses  first  metatarsal,  abducts  fore  foot,  rotates  out. 

Flexors  and  extensors  of  toes,  interossei,  and  lumbri«ales  act  like  the  cor- 
responding muscles  of  the  hand. 

Flex,  accessorius  modifies  the  action  of  the  flex.  long,  dig.,  as  those  tendons 
cannot  enter  the  foot  in  a  straight  line. 

The  extensor  brevis  dig.  does  the  same  for  the  extensor  communis,  tholigh 
here  they  are  not  so  much  needed,  and  their  function  is  not  so  evident. 

Extensors  of  foot  slightly  rotate  in  ;  flexors  of  foot  slightly  rotate  out ; 
plantaris  indirectly  pulls  up  the  capsule  of  ankle-joint  and  slightly  aids  the 
gastrocnemius. 

Flexors  of  Foot.  Extensors  of  Foot. 

Tibialis  anticus.  Tendo  Achillis. 

Extens.  communis  dig.  Peroneus  long,  and  brevis. 

Extens.  propr.  hall.  Tibialis  posticus. 

Peroneus  tertius.  Flex.  long,  digit,  and  hall. 

Additction.  Abduction. 

Tibialis  post,  (strongly).  Peroneus  brevis. 

Tendo  Achillis  (weakly).  Peroneus  longus. 

Perhaps  tendons  behind  inner  mall., 
•  perhaps  tibialis  anticus. 

Rotation  in.  Rotation  out. 

Tibialis  anticus  (strongly).  Peroneus  longus. 

Tendo  Achillis.  Extens.  communis  dig. 

Peroneus  tertius. 


202 


MUSCLES   AND   FASCIA.   OF   THE   EXTREMITIES. 


The  muscles  of  the  foot,  especially  of  the  little  toe-side,  are  decreasing  and 
the  little  toe  becoming  less  important ;  those  of  the  hand  are  increasing,  cor- 
responding to  its  complex  movements  over  those  of  the  foot. 

In  comparing  muscles  of  leg  with  forearm  we  notice  (1)  a  reduction  in  ac- 
cordance with  diminution  of  mobility;  (2)  disappearance  of  high  origin  of 
some  superficial  extensors ;  (3)  development  of  tarsal  attachment  of  super- 
ficial flexors  of  toes  due  to  outgrowth  of  heel. 


MUSCULAR  HOMOLOGIES. 

I.  Muscles  from  Trunk  to  Limbs  or  from  Girdle  to  Humerus 

or  Feruur. 

Upper  Limb. 
Trapezius, 
Cleido-mastoid, 
Rhomboidei, 
Lev.  ang.  scapulae, 
Serratus  magnus, 

Deltoid, 

Teres  minor. 
Latissimus  dorsi. 
Teres  major. 

Pectoral  is  major. 

Pectoral  is  minor. 
Subclavius. 

Supraspinatus. 
Infraspinatus, 


Subscapularis, 

Coraco-brachialis, 
Chondro-epitrochlearis, 


Lower  Limb. 


■  Ext.  oblique  and  lumbar  aponeurosis. 


Tensor  vag.  femoris. 

Gluteal  fascia. 

Gluteus  maximus,  upper  part. 

Gluteus  maximus,  larger  part. 

Adductor  longus. 
Adductor  brevis. 


Psoas. 

Iliacus. 

Pectineus. 

Gluteus  medius. 

Gluteus  minimus. 

Pyriformis. 

Obturator  internus  with  Gemelli. 

Obturator  externus. 

Quadratus  femoris. 

Adductor  magnus. 

Gracilis. 


n.  Muscles  of  Arm  and  Thigh. 


Biceps, 

Humeral  head  of  biceps, 
Brachialis  anticus, 
Dorso-epitrochlearis, 
Triceps : 

a.  Scapular  head. 

b.  Humeral  heads. 
Anconeus. 


Ischial  head  of  biceps  fem. 

Semitendinosus. 

Semimembranosus. 

Femoral  head  of  biceps  fem. 

Sartorius. 
Quadriceps : 

a.  Eectus  femoris. 

b.  Vasti  and  crureus. 


MUSCULAR   HOMOLOGIES. 


203 


III.  Muscles  of  Forearm  and  Leg*. 


Pronator  teres, 
Flexor  carpi  radialis, 
Flexor  carpi  uluaris, 
Palmaris  longus, 
Flexor  sublimis  digitorum, 
Flexor  longus  pollicis, 
Flexor  profundus  digit., 

Lumbricales, 

Pronator  quadratus. 

Ulno-carpeus, 

Radio-carpeus, 

Supinator  longus. 

Extensor  carpi  radialis  longior. 

Extensor  carpi  radialis  brevior. 

Extensor  communis  digit., 

Extensor  minimi  digiti. 

Extensor  carpi  ulnaris, 

Supinator  brevis. 
Extensor  ossis  metacarpi  poll., 
Extensor  longus  poll.. 
Extensor  brevis  poll., 

Extensor  indicis. 

Extensor  medii  digiti, 
Extensor  brevis  digitorum^ 


II 


Popliteus. 

Gastrocnemius. 

Plantaris. 

Soleus  and  flexor  brevis  digit. 

Flexor  longus  hallicis. 

Flexor  longus  digit. 

Flexor  accessorius. 

Lumbricales. 

Per oneo- calcaneus  internus. 
Tibialis  posticus. 


Extensor  longus  digit. 
Peroneus  tertius  (?). 
Peroneus  longus. 
Peroneus  brevis. 

Tibialis  anticus. 
Extensor  longus  hall. 
First  slip  of  extensor  brevis  digitorum. 
Second   slip  of  extensor  brevis  digj 
torum. 


1 

\  Extensor  brevis  digit. 


IV.  Muscles  of  Hand  and  Foot. 


Palmaris  brevis. 
Abductor  pollicis, 
Flexor  brevis  pollicis, 
Opponens  pollicis, 
Adductor  obliquus  pollicis, 
Adductor  transversus  pollicis, 
Abductor  minimi  digiti. 
Flexor  brevis  minimi  digiti. 
Opponens  minimi  digiti. 
a.  Superficial  part. 

h.  Deep  part, 

First  palmar  interosseous. 

Second  palmar  interosseous. 
Other  interossei  correspond. 


Abductor  hallicis. 
Flexor  brevis  hallicis. 
Opponens  hallicis. 
Adductor  obliquus  hallicis. 
Adductor  transversus  hallicis. 
Abductor  minimi  digiti. 


I  Flexor  brevis  min.  dig. 
(  Opponens  min.  dig. 

First  plantar  interosseous. 
Second  plantar  interosseous. 


204  THE   HEAET. 


ANGEIOLOGY. 

THE  HEART. 
Describe  the  pericardium. 

The  pericardium  is  a  fibro-serous  membrane  which  invests  the  heart 
and  the  great  vessels  at  their  origin  for  about  2  inches.  Below  it  is 
attached  to  the  diaphragm  and  its  central  tendon ;  in  front  it  is  sep- 
arated fi-om  the  sternum  by  the  thymic  remains,  some  areolar  tissue,  and 
overlapped  by  the  margins  of  the  lungs,  especially  of  the  left ;  behind  it 
are  the  oesophagus,  bronchi,  and  descending  aorta ;  laterally  it  is  cov- 
ered by  the  pleurae,  with  the  phrenic  nerve  and  vessels  running  between 
the  two  membranes. 

The  pericardium  consists  of  a  fibrous  and  a  serous  layer.  The  fibrous 
layer  forms  a  tubular  investment  for  the  great  vessels  which  is  lost  on 
the  external  coat,  and  can  be  traced  afterward  into  the  deep  cervical 
fascia.  It  is  attached  below  to  the  diaphragm  and  its  central  tendon. 
The  vessels  invested  are  the  aorta,  superior  vena  cava,  both  pulmonary 
arteries,  and  all  the  pulmonary  veins. 

The  serous  layer  invests  the  heart  and  is  reflected  on  to  the  fibrous 
layer.  It  also  invests  the  great  vessels  for  about  2  inches.  The  aorta 
and  pulmonary  artery  are  completely  invested,  the  pulmonary  veins  and 
both  the  venae  cavae  only  partially. 

Describe  the  heart. 

The  heart  is  a  hollow  muscular  organ,  of  a  somewhat  conical  form, 
lying  between  the  lungs  and  enclosed  by  the  pericardium.  It  contains 
four  cliambers,  an  auricle  and  a  ventricle  on  each  side. 

Give  its  general  position  and  measurements. 

It  lies  obliquely,  the  base  being  directed  upward,  backward,  and  toward 
the  right,  and  extending  from  the  level  of  the  fifth  to  that  of  the  eighth 
dorsal  vertebra,  and^  the  apex  looking  downward,  forward,  and  to  the 
left,  its  impulse  against  the  chest-wall  being  felt  in  the  fifth  left  inter- 
space, about  3?  inches  from  the  middle  of  the  sternum.  The  heart  lies 
more  in  the  left  than  in  the  right  side  of  the  chest,  its  base  being  held 
in  position  by  the  great  vessels  which  are  connected  with  it ;  its  posterior 
surface  is  flat,  formed  chiefly  by  the  left  ventricle,  and  rests  on  the  dia- 
phragm ;  and  its  anterior  surface,  formed  chiefly  by  the  right  ventricle, 
but  also  partly  by  the  left,  is  convex  and  covered  to  some  extent  by  the 
lungs.  Of  the  borders,  the  right  is  long  and  thin,  and  the  left  is 
shorter  and  thick.  The  length  of  the  heart  is  5  inches ;  its  greatest 
breadth  is  3J  inches;  its  thickness  is  about  2J  inches.  Its  weight 
is  10  to  12  ounces  in  the  male,  8  to  10  in  the  female,  and  it  increases 
with  age. 


THE   HEART.  ^^0|U*"""'"'"*N.2O5 

How  is  the  heart  subdivided  externally  ? 

Externally  it  presents  a  deep  transverse  groov#  the  auriculo- ventricu- 
lar, which  marks  off  an  upper  or  auricular  any  ab  lo^er  or  ventricular  1 
portion :  this  latter  part  presents  a  longitudinalfmrolrt  ^LMf  jlML^  It^ft  1 
back,  the  former  being  somewhat  to  the  left,  tl^  latter  to  the  ngfm  ^^  "<.| 

How  is  the  heart  subdivided  internally  ? 

The  interior  of  the  heart  is  divided  by  a  longl^^kial  septum  inj^ 
right  and  left  part,  and  these,  in  turn,  are  divided  nj^^yL  auric 
ventricle.  ^^^^^» 

Describe  the  right  auricle. 

The  right  auricle  is  larger  than  the  left,  its  wall  being  about  1  line 
in  thickness  and  its  capacity  two  ounces.  Its  cavity  is  divided  into  two 
parts,  the  sinus  venosus  and  the  appendix  auriculae,  the  former  lying 
between  the  entrances  of  the  two  venae  cavae,  the  latter  overlapping  the 
commencement  of  the  aorta.  ^  Within  the  auricle  the  following  parts 
present  themselves  for  examination: 

(1)  The  orifice  of  the  superior  vena  cava,  looking  downward  and 
forward. 

(2)  The  orifice  of  the  inferior  vena  cava,  at  the  lowest  part,  near  the 
septum,  looking  upward  and  inward.^ 

(3)  Between  the  two  caval  openings  a  projection,  the  tuberculum 
Loweri. 

(4)  The  opening  of  the  coronary  sinus,  between  the  inferior  cava  and 
the  auriculo-ventricular  opening,  and  protected  by  the  fold  of  endocar- 
dium forming  the  coronary  valve. 

(5)  Numerous  small  openings  (foramina  Thebesii)  of  the  venae  cordis 
minimae. 

(6)  The  auriculo-ventricular  opening. 

(7)  The  Eustachian  valve,  between  the  front  of  the  vena  cava  and 
the  above-mentioned  orifice.  It  is  semilunar  in  form,  the  free  concave 
margin  sending  one  cornu  to  join  the  front  of  the  annulus  ovalis  and  the 
other  to  the  auricular  wall. 

(8)  The  fossa  ovalis,  at  the  back  of  the  septum,  in  the  situation  of  the 
foetal  foramen  ovale,  its  prominent  margin  being  known  as  the  annulus 
ovalis. 

(9)  The  musculi  pectinati,  small  elevated  columns  which  traverse  the 
appendix  and  the  adjacent  part  of  the  sinus. 

Describe  the  right  ventricle. 

The  right  ventricle  is  triangular,  and  extends  nearly  to  the  apex  of  the 
heart.  It  is  bounded  internally  by  the  convex  surface  of  the  septum 
ventriculorum,  and  prolonged  above  and  internally  into  a  pouch,  the  in- 
fundibulum,  or  conus  arteriosus,  from  which  springs  the  pulmonary 
artery.  Its  cavity  has  a  capacity  of  three  ounces.  On  opening  the 
ventricle  the  following  parts  are  presented  for  examination: 


206  •  THE   HEART. 

^  (1)  The  auriculo-ventricular  orifice,  oval  in  form  and  placed  near  the 
right  side  of  the  heart.  Around  its  circumference  is  a  fibrous  ring,  arid 
it  is  guarded  by  the  tricuspid  valve. 

(2)  The  opening  of  the  pulmonary  artery,  circular  in  form,  at  the 
summit  of  the  conus  arteriosus,  near  the  septum ;  is  guarded  by  the  pul- 
monary valve  (semilunar). 

(3)  The  tricuspid  valve  consists  of  three  triangular  flaps  formed  of 
fibrous  tissue  covered  by  endocardium.  They  are  continuous  with  one 
another  at  their  bases,  and  their  free  margins  and  ventricular  surfaces 
give  attachment  to  the  chordse  tendineaB.  Their  central  part  is  thick 
and  strong,  the  lateral  margins  thinner  and  flexible. 

(4)  The  chordaB  tendineae  are  attached  as  follows :  several  to  the  at- 
tached margin  of  each  flap,  blending  with  the  fibrous  ring ;  several  to 
the  strong  central  part ;  and  the  finest  and  most  numerous  to  the  mar- 
gins of  each  curtain. 

(5)  The  columnae  carneaB  are  projecting  bundles  of  muscular  substance 
found  all  over  the  ventricular  wall  excepting  the  conus  arteriosus.  They 
are  of  three  classes :  the  first  are  mere  ridges,  attached  by  one  side  and 
both  extremities;  the  second  are  attached  only  by  both  extremities; 
the  third  (musculi  papillares)  are  attached  by  only  one  extremity,  the 
free  end  having  chordae  tendineae  attached  to  it. 

(6)  The  three  semilunar  valves  guard  the  pulmonary  orifice.  They 
are  semicircular,  their  free  margins  being  thick  and  tendinous  and  pre- 
senting at  the  middle  a  small  fibrous  nodule,  the  corpus  Arantii.  On 
each  side  of  this  body,  just  behind  the  free  margin,  the  valve  presents  a 
small  thinned-out  interval,  and  when  the  valves  are  closed  during  dias- 
tole these  intervals  {lunidce)  are  in  contact,  and  so  also  are  the  three 
nodules.  These  latter  prevent  any  leakage  from  the  triangular  space 
which  would  otherwise  be  left.  At  the  commencement  of  the  pulmo- 
nary artery  are  three  pouches,  the  sinuses  of  Valsalva,  placed  one  be- 
hind each  valve.     They  resemble  those  of  the  aorta,  but  are  smaller. 

Describe  the  left  auricle. 

It  is  smaller  and  thicker-walled  than  the  right,  and  consists,  like  the 
right,  of  a  sinus  and  an  appendix.  The  latter  overlaps  the  pulmonary 
artery.     Within  it  presents  the  following  features  of  interest : 

The  orifices  of  the  pulmonary  veins,  opening  two  into  the  right  and 
two  into  the  left  side ;  the  auriculo-ventricular  orifice ;  and  a  few  mus- 
culi pectination  the  inner  side  of  the  appendix. 

Describe  the  left  ventricle. 

It  is  longer  than  the  right,  and  enters  into  the  formation  of  the  apex. 
Its  walls  are  three  times  as  thick  as  those  of  the  right.  Within  it  pre- 
sents for  examination — 

The  auriculo-ventricular  orifice,  which  is  smaller  than  the  right  and 
guarded  by  the  mitral  or  bicuspid  valve ;  and  the  aortic  opening,  in  front 
and  to  the'  right  of  the  preceding,  guarded  by  the  semilunar  valves. 


PLATE  XV. 

Fig.  1 . — To  fax^e  page  205. 


Bristle  passed  through 
Eight  AuriciUo- Ventricular  opening. 


PLATE  XVI. 

Fig.  1 . — To  face  page  i 


Right  vagus. 
Recurrent  laryngeal. 


Left  vagus. 
Left  phrenic. 
Thoracic  duct. 


The  Arch  of  the  Aorta  and  its  Branches. 


STRUCTURE   OF   THE   HEART.  207 

The  mitral  valve  is  attached,  like  the  tricuspid  on  the  right  side.  It 
consists  of  two  curtains  which  are  larger  and  thicker  than  those  of  the 
tricuspid,  and  of  two  smaller  segments,  one  at  each  angle  of  junction  of 
the  former.     They  are  furnished  with  chordae  tendineae. 

The  aortic  semilunar  valves  are  similar  to  but  larger  and  stronger  than 
the  pulmonary  valves. 

Columnae  carneae  are  found  as  in  the  right  ventricle,  and  the  musculi 
papillares  consist  of  two  groups  and  are  very  large. 

The  inner  surface  of  the  heart  is  lined  by  a  thin  membrane,  the  endo- 
cardium, continuous  with  the  inner  lining  of  the  great  blood-vessels,  and 
helping  to  form  by  its  folds  the  various  valves. 

The  heart  is  supplied  with  blood  by  the  coronary  arteries,  and  with 
nerves  by  the  cardiac  plexuses,  formed  by  branches  of  the  pneumogas- 
tric  and  sympathetic  nerves. 

STRUCTURE   OF  THE  HEART. 
What  are  the  two  structures  of  which  the  heart  is  made  up  ? 

Fibrous  rings  and  muscular  fibres :  the  former  serve  as  points  of  at- 
tachment of  the  latter. 

What  is  the  situation  of  the  fibrous  rings  ? 

They  surround  the  auriculo-ventricular  and  arterial  orifices,  and  give 
attachment  to  the  valves  of  the  heart  and  great  vessels,  in  addition  to 
the  muscular  attachment. 

How  may  the  muscular  fibres  be  divided? 

1 .  Into  those  of  the  auricles ;  2.  those  of  the  ventricles. 

Describe  the  arrangement  of  the  fibres  of  the  auricles. 

These  are  in  two  layers,  a  superficial  and  a  deep.  The  former  layer  is 
common  to  both  auricles ;  the  latter  is  peculiar  to  each.  The  superficial 
layer  passes  across  from  one  auricle  to  the  other  anteriorly,  and  back 
again  posteriorly,  thus  enclosing  them  in  a  kind  of  ring.  The  deep  layer 
is  made  up  of  looped  and  annular  fibres.  The  looped  fibres  arch  over 
the  auricle ;  the  annular  fibres  encircle  each  auricle. 

Describe  the  arrangement  of  the  fibres  of  the  ventricles. 

There  are  seven  layers  in  each  ventricle :  in  the  left  ventricle  the  fibres 
of  the  first  or  most  external  layer  are  continuous  with  the  fibres  of  the 
seventh  or  most  internal  layer ;  those  of  the  second  with  the  sixth,  those 
of  the  third  with  the  fifth,  while  the  fourth  layer  runs  horizontally  and 
continuously  around  the  ventricle.  The  direction  of  the  other  layers  is 
as  follows:  first  layer,  from  above  downward  and  from  left  to  right; 
seventh  layer,  just  the  opposite ;  second  layer,  like  the  first,  but  more 
obliquely ;  sixth  layer,  just  the  reverse ;  while  the  third  and  fifth  layers 
are  nearly  horizontal.  The  union  of  the  first  and  seventh  layers  is  at 
the  apex  of  the  heart,  and  forms  the  vortex  or  whorl.     In  the  right 


208  SYSTEMIC   ARTERIES. 

ventricle,  arrangement  exactly  the  same,  except  union  of  first  and  seventh 
layers,  which  takes  place  all  along  the  anterior  coronary  groove.  All 
the  fibres  are  much  more  delicate  than  those  of  the  left  ventricle. 

ARTERIES. 
Describe  the  pulmonary  artery. 

It  is  a  short,  wide  vessel,  2  inches  in  length.  Commencing  at  the 
base  of  the  right  ventricle,  it  curves  upward  and  backward,  to  end 
under  the  transverse  aorta  by  dividing  into  a  right  and  a  left  branch. 
Relations :  in  front,  second  left  intercostal  space  and  cartilage,  left  bor- 
der of  sternum ;  behind,  origin  of  aorta,  left  auricle ;  above,  transverse 
aorta,  remains  of  ductus  arteriosus ;  to  the  right,  right  appendix  and 
coronary  artery,  ascending  aorta ;  to  the  left,  left  appendix  and  coronary 
artery. 

This  vessel,  with  the  ascending  aorta,  is  enclosed  in  a  sheath  of  peri- 
cardium. It  winds  around  the  aorta,  being  at  first  in  front,  and  later  to 
the  left  side,  of  the  ascending  portion.  In  foetal  life  the  ductus  arteri- 
osus connects  it  a  little  to  the  left  of  its  bifurcation  with  the  transverse 
aorta. 

Each  branch  enters  the  root  of  the  corresponding  lung ;  the  right,  the 
larger,  passing  behind  the  ascending  aorta  and  superior  vena  cava ;  the 
left,  in  front  of  the  descending  aorta.  The  left  divides  into  two  branches 
for  the  lobes  of  the  left  lung ;  the  right  also  divides  into  two  primary 
branches  for  the  upper  and  lower  lobes.  From  the  lower  one  of  these  is 
sent  a  branch  to  the  middle  lobe. 


SYSTEMIC  ARTERIES. 
Describe  the  aorta. 

The  aorta  is  the  main  trunk  from  which  spring  the  sj^stemic  arteries. 
From  the  base  of  the  left  ventricle  it  runs  upward,  forward,  and  to  the 
right  as  far  as  the  second  right  cartilage ;  then  backward  and  to  the  left, 
over  root  of  left  lung,  to  the  fourth  dorsal  vertebra ;  thence,  along  the 
spine,  it  descends  through  the  thorax  and  abdomen  to  divide,  at  the 
fourth  lumbar,  into  the  common  iliacs. 

It  has  been  divided,  for  convenience  of  description,  into  the  arch  and 
the  descending  aorta.  The  arch  is  subdivided  into  the  ascending,  trans- 
verse, and  descending  parts ;  the  descending  aorta,  into  the  thoracic  and 
abdominal  portions. 

ARCH  OF  THE  AORTA  AND  ITS  BRANCHES. 
Describe  the  ascending  part  of  the  arch. 

It  runs  upward,  forward,  and  to  the  right,  from  a  point  opposite  the 
lower  border  of  the  third  left  cartilage,  to  the  upper  border  of  the  second 


ARTEEIES   OF   THE   HEAD,    ETC.  209 

right  cartilage.  Close  to  its  origin  it  presents  three  small  dilatations,  the 
sinuses  of  Valsalva,  indicating  the  situation  of  the  semilunar  valves,  and 
along  the  right  side  a  bulging,  the  siinis  magnus.  Relations  :  in  front, 
pulmonarj^  artery,  right  appendix,  thoracic  fascia,  right  pleura,  pericar- 
dium, remains  of  the  thymus  gland  ;  behind,  root  of  right  lung,  including 
right  pulmonary  vessels,  left  auricle ;  to  the  right,  right  auricle,  supe- 
rior vena  cava ;  to  the  left,  pulmonary  artery. 

Describe  the  transverse  part  of  the  arch. 

This  part  passes  backward  and  to  the  left  as  far  as  the  left  side  of 
body  of  the  fourth  dorsal  vertebra.  Relations:  in  front,  lungs  and 
pleura,  thymic  remains,  left  vagus,  phrenic  and  superficial  cardiac 
nerves,  left  superior  intercostal  vein ;  behind,  trachea,  oesophagus,  tho- 
racic duct,  deep  cardiac  plexus,  left  recurrent  nerve ;  above,  left  innom- 
inate vein  and  the  branches  of  this  portion  of  the  aorta — viz.  innom- 
inate, left  carotid,  and  subclavian  arteries ;  below,  left  bronchus, 
biiiircation  of  pulmonary  artery,  ductus  arteriosus,  left  recurrent  nerve. 

Describe  the  descending  part  of  the  arch. 

It  descends  to  lower  border  of  fifth  dorsal  vertebra,  ending  in  the 
thoracic  aorta.  Relations  :  in  front,  root  of  left  lung  covered  by  pleura ; 
behind,  left  side  of  body  of  fifth  dorsal  vertebra ;  right  side,  oesophagus, 
thoracic  duct ;  left  side,  left  lung,  covered  by  pleura. 

Name  and  describe  the  branches  of  the  arch  of  the  aorta. 

They  are  five :  coronary,  right  and  left,  from  the  ascending  part ;  and 
the  innominate,  left  carotid,  and  left  subclavian,  from  the  transverse 
part.     The  descending  part  gives  off  no  branches. 

The  coronary  arteries  supply  the  heart  and  the  coats  of  the  great  ves- 
sels. They  emerge  on  either  side  of  the  pulmonary  artery,  between  it 
and  the  corresponding  appendix  auriculae.  Each  arises  from  a  sinus  of 
•  Valsalva,  just  above  the  free  margin  of  the  corresponding  semilunar 
valve,  and  is  distributed  to  the  muscular  substance  of  the  heart,  its 
valves  and  septa,  running  along  the  grooves  on  its  surfaces,  and  anasto- 
mosing freely  with  the  other,  and,  by  means  of  twigs  to  the  aorta  and 
pulmonary  artery,  with  the  pericardiac  and  bronchial  vessels.  Each 
divides  into  two  primary  branches,  the  right  vessels  running  in  the  pos- 
terior and  the  left  in  the  anterior  grooves. 

ARTERIES  OP  THE  HEAD,  NECK,  AND  UPPER 
EXTREMITY. 

Describe  the  innominate  artery  (brachio-cephalic). 

This  is  the  largest  branch.  It  arises  in  front  of  the  left  carotid,  and 
runs  obhquely  to  the  right  sterno-clavicular  joint,  where  it  divides  into 
the  right  common  carotid  and  right  subclavian.  Relations :  in  front, 
manubrium  sterni,  sterno-hyoid  and  thyroid  muscles,  thymic  remains, 
left  innominate  and  right  inferior  thyroid  veins,  inferior  cervical  cardiac 
14— A, 


210  SYSTEMIC  ABTERIES. 

nerve  from  right  vagus ;  behind,  trachea  and  pleura ;  right  side,  pleura, 
right  vagus,  right  phrenic  nerve,  and  the  right  innominate  vein ;  left 
side,  remains  of  the  thymus  and  trachea.  The  left  carotid  artery  is 
behind  and  to  the  left  of  this  vessel.  The  innominate  regularly  gives 
oiF  no  branches.  Occasionally,  however,  a  thymic  or  bronchial  branch 
or  the  arteria  thyroidea  ima  arises  from  it. 

Describe  the  common  carotid  arteries. 

They  are  identical  in  course,  branches,  and  relations  in  the  neck,  but 
differ  in  their  origin.  Thus,  the  right  is  a  branch  of  bifurcation  of  the 
innominate,  while  the  left  is  a  primary  branch  of  the  transverse  aorta. 
From  its  origin  the  left  carotid  passes  obliquely  upward  and  outward  to 
the  left  sterno-clavicular  joint,  and  from  that  point  follows  a  course  cor- 
responding to  that  of  the  right  carotid.  We  describe,  therefore,  a  tho- 
racic portion  of  the  left  carotid  artery.  Its  relations  are  as  follows :  in 
front,  sternum,  sterno-hyoid  and  thyroid,  thymic  remains,  left  innom- 
inate vein ;  behind,  trachea,  oesophagus,  thoracic  duct ;  left  side,  left 
subclavian  artery,  left  vagus ;  right  side,  innominate  artery,  which  is  also 
somewhat  in  front. 

In  the  neck  each  carotid  ascends  from  the  sterno-clavicular  joint  to  the 
level  of  the  upper  border  of  the  thyroid  cartilage,  there  dividing  into 
the  external  and  internal  carotids.  Each  is  enclosed,  with  the  internal 
jugular  vein  and  vagus,  in  a  sheath  of  deep  cervical  fascia,  the  several 
structures  being  partitioned  from  one  another  within  the  sheath.  The 
artery  is  internal,  the  vein  external,  the  nerve  between  them,  but  on  a 
posterior  plane.  Relations:  in  fronts  integument,  fasciae,  platysma, 
sterno-mastoid,  hyoid,  thyroid,  and  omo-hyoid  muscles,  descendens  and 
communicantes  noni  nerves,  sterno-mastoid  artery,  superior,  middle  thy- 
roid, and  anterior  jugular  veins,  and  a  branch  connecting  anterior  jugular 
with  facial;  behind,  longus  coUi,  rectus  anticus  major,  spinal  column, 
inferior  thyroid  artery,  sympathetic  and  recurrent  laryngeal  nerves; 
outer  side,  internal  jugular  vein,  vagus ;  inner  side,  trachea,  oesophagus, 
larynx,  pharynx,  thyroid  gland,  inferior  thyroid  artery,  and  recurrent 
nerve.  In  the  lower  part  of  the  neck  the  internal  jugular  diverges  from 
the  artery  on  the  right  side,  but  approaches,  and  may  cross  it,  on  the 
left.  The  common  carotid  regularly  gives  off  no  branches,  but  a  verte- 
bral, thyroid,  or  laryngeal  branch  may  arise  from  it  on  either  side. 

Describe  the  external  carotid  artery. 

This  vessel  runs  from  the  bifurcation  of  the  common  carotid  to  the 
neck  of  the  lower  jaw,  and  there  divides  into  the  superficial  temporal 
and  internal  maxillary.  ^  At  its  origin  it  is  anterior  and  internal  to  the 
internal  carotid,  and  at  its  termination  is  imbedded  in  the  parotid  gland. 
Relations :  in  front,  integument  and  fasciae,  sterno-mastoid,  digastric,  and 
stylo-hyoid  muscles,  part  of  parotid,  facial  and  hypoglossal  nerves,  lin- 
gual, facial,  and  temporo-maxillary  veins ;  behind,  styloid  process  with 
its  remaining  muscles,  part  of  parotid  gland,  and  the  glosso-pharyngeal 


ARTEEIES   OF   THE   HEAD,   ETC.  211 

nerve ;  internally^  pharynx,  hyoid  bone,  part  of  parotid,  separating  it 
from  the  lower  jaw  and  stylo-maxillary  ligament,  and  the  superior  laryn- 
geal nerve. 

Name  and  describe  the  branches  of  the  external  carotid. 

Besides  branches  given  off  directly  to  the  muscles  in  its  course  and  to 
the  parotid  gland,  they  are  the  following :  Anterior  branches,  superior 
thyroid,  lingual,  facial ;  posterior  branches,  occipital,  posterior  auricular ; 
internal  branch,  ascending  pharyngeal;  terminal  branches,  superficial 
temporal  and  internal  maxillary. 

I.  The  superior  thyroid  runs  beneath  the  omo-hyoid  and  sterno- 
hyoid and  thyroid  muscles  to  the  gland,  uniting  with  its  fellow  and  with 
the  inferior  thyroid.  It  supplies  the  gland,  the  muscles  in  its  course, 
and  the  following-named  branches: 

{a)  Hyoid,  to  lower  border  of  bone,  joins  its  fellow. 

(b)  Superficial  descending  or  sterno-mastoid  crosses  common  carotid 
to  the  sterno-mastoid  muscle. 

(r)  Superior  laryngeal,  beneath  thyro-hyoid,  pierces  membrane  to  in- 
terior of  larynx. 

(d)  The  crico-thyroid  runs  across  that  membrane  and  joins  its  fellow. 

II.  The  lingual  ascends  to  the  great  cornu  of  the  hyoid  bone,  runs 
forward  parallel  with  it,  ascends  to  the  tongue,  and  runs  along  its  under 
surface  to  the  tip.  It  is  at  first  superficial,  lying  on  middle  constrictor ; 
later  covered  by  digastric  and  stylo-hyoid,  resting  on  the  same  muscle. 
It  then  ascends  between  the  hyoglossus  and  genioglossus ;  finally,  as  the 
ranine  artery,  it  runs  on  the  lingualis  to  tip  of  tongue,  along  with  the 
gustatory  nerve,  covered  only  by  mucous  membrane.  The  first  part  is 
crossed  by  the  hypoglossal  nerve.  The  second  part  is  in  the  triangle 
formed  by  the  diverging  bellies  of  the  digastric  below  and  the  hypo- 
glossal nerve  above.  The  artery  lies  above  the  central  tendon  of  the 
digastric,  below  the  nerve,  and  beneath  the  hyoglossus.     Branches: 

(a)  Hyoid,  to  upper  border  of  hyoid  bone,  joins  its  fellow. 
Q))  Dorsalis  linguce,  from  beneath  the  hyoglossus,  joins  its  fellow,  and 
supplies  the  tonsil,  epiglottis,  and  soft  palate,  besides  the  tongue. 

(c)  Sublingual  runs  on  genio-glossus  to  the  gland.  Branches  supply  the 
mylo-hyoid  and  gums,  and  a  twig  joins  its  fellow  across  the  middle  line. 

III.  The  facial  runs  under  the  lower  jaw  upon  mylo-hyoid,  and 
grooves  the  upper  and  back  part  of  the  submaxillary  gland.  It  then 
crosses  the  jaw  at  the  anterior  border  of  the  masseter,  runs  over  the 
cheek  by  the  angle  of  the  mouth,  and  alongside  of  the  nose  to  the  inner 
canthus  of  the  eye,  ending  in  the  angular  artery,  which  anastomoses 
with  the  nasal  branch  of  the  ophthalmic.     Its  course  is  very  tortuous. 

This  vessel  lies  at  first  beneath  the  digastric  and  stylo-hyoid,  but  is 
covered  only  by  the  platysma  where  it  crosses  the  jaw.  In  the  face  it 
lies  on  the  buccinator,  levator  anguli  oris,  and  levator  labii  superioris, 
covered  by  the  platysma,  risorius,  and  zygomatici.  The  vein  is  external 
and  at  some  distance  from  the  artery,  and  pursues  a  straight  course. 


212  SYSTEMIC  ARTERIES. 

Branches  of  the  facial  nerve  cross,  and  the  infraorbital  nerve  is  under, 
the  artery. 

Its  branches  are  the  following :  a  cervical  group,  including  the  inferior 
palatine,  tonsillar,  submaxillary,  submental;  and  a/aczor7group:  the  in- 
ferior labial,  coronary  upper  and  lower,  lateralis  nasi,  and  the  angular. 

{a)  The  inferior  or  ascending  palatine  runs  at  first  between  the  stylo- 
glossus and  pharyngeus ;  then  between  the  internal  pterygoid  and  phar- 
ynx. It  crosses  the  superior  constrictor  to  the  soft  palate,  joins  its  fel- 
low, and  supplies  the  tonsil,  Eustachian  tube,  palate,  and  the  muscles 
along  its  course. 

{h)  The  tonsillar  pierces  superior  constrictor  to  tonsil  and  tongue. 

(c)  The  siibmaxillai-y  includes  several  glandular  branches. 

\d)  The  submental^  the  largest  branch,  runs  beneath  the  jaw,  sending 
twigs  through  the  mylo-hyoid  to  join  the  sublingual.  It  turns  over  the 
symphysis,  giving  offsets  to  the  chin  and  lower  lip,  and  joins  its  fellow 
and  the  inferior  dental.     It  supplies  also  the  muscles  along  its  course. 

[e)  Muscular  branches  are  derived  from  the  vessel  at  every  point,  both 
in  the  face  and  neck. 

(/)  The  inferior  labial^  beneath  the  depressor  anguli  oris,  joins  mental, 
submental,  and  inferior  coronary. 

{g)  The  coronary  arteries  ramify  between  the  orbicularis  oris  and  the 
mucous  membrane,  the  inferior  joining  its  fellow  and  the  inferior  labial ; 
the  superior,  arising  from  behind  the  zygomaticus  major,  gives  off  the 
artery  of  the  septum,  besides  other  nasal  branches. 

(/i)  Lateralis  nasi,  to  side  of  nose. 

(i)  Angular  is  the  terminal  branch. 

IV.  The  occipital  artery  is  at  first  covered  by  the  digastric  and 
stylo-hyoid  muscles  and  crossed  by  the  hypoglossal  nerve.  It  then 
crosses  the  internal  carotid  sheath  and  spinal  accessory  nerve  to  the  in- 
terval between  the  atlas  and  mastoid  process,  lying  here  in  the  occipital 
groove,  and  then  pierces  the  origin  of  the  trapezius  to  ramify  in  the 
scalp  as  high  as  the  vertex.     Branches  : 

{a)  Muscular,  all  along  its  course. 

(6)  The  sterno-mastoid  branch  enters  the  muscle  with  the  spinal  ac- 
cessory nerve. 

(c)  The  mastoid  branch,  through  the  mastoid  foramen. 

(d )  Princeps  cervicis  divides  into  a  superficial  branch,  lying  under  the 
splenius,  and  sending  twigs  through  it  to  anastomose  with  the  super- 
ficial cervical ;  and  a  deep  branch  beneath  the  complexus,  to  join  branches 
of  the  vertebral  and  profunda  cervicis. 

(e)  A  meningeal  branch  enters  the  jugular  foramen. 

V.  The  posterior  auricular  artery,  resting  on  the  styloid  pro- 
cess, passes  beneath  the  parotid  to  the  groove  between  mastoid  and 
auricle,  and  divides  into  two  branches,  the  auricular  and  mastoid,  the 
latter  supplying  the  scalp.  This  artery  crosses  the  spinal  accessory  and 
is  crossed  by  the  facial  nerve.  Besides  branches  to  the  various  muscles 
and  the  parotid,  it  gives  off  the  following : 


AETERIES   OF   THE   HEAD,    ETC.  213 

(a)  The  sfyh-mastoid,  through  the  foramen,  to  the  mastoid  cells  and 
tympanum.  In  the  young  subject  a  branch  joins  the  tympanic  from  the 
internal  maxillary  artery  to  form  a  circle,  from  which  twigs  pass  to  the 
tympanic  membrane.  Another  branch,  in  the  aqueductus  Fallopii,  joins 
the  petrosal  artery  of  the  middle  meningeal. 

{h)  The  auricular^  anastomosing  with  branches  of  the  temporal. 

VI.  The  ascending  pharyngeal  ascends  between  pharynx  and  in- 
ternal carotid  to  the  base  of  the  skull,  giving  off  branches  which  may  be 
divided  into  three  sets — viz.  (1)  three  or  four  pharyngeal^  to  the  con- 
strictors, the  lower  joining  branches  of  the  superior  thyroid,  and  the 
largest  to  the  superior  constrictor,  supplying  also  the  palate  and  tonsil. 
(2)  Several  meningeal  branches  entering  the  foramen  lacerum  me- 
dium, jugular  and  anterior  condylar  foramina.  (3)  The  prevetiebral 
branches,  to  the  muscles  and  glands  in  its  course  and  to  the  vagus  and 
sympathetic  nerves,  anastomosing  with  the  ascending  cervical. 

The  external  carotid  divides  into  the  superficial  temporal  and  in- 
ternal maxillary  while  imbedded  in  the  parotid  gland,  the  former  being 
the  smaller. 

VII.  The  superficial  temporal  ascends  to  about  2  inches  above 
the  zygoma,  and  divides  into  the  anterior  and  posterior  temporal  The 
former  suppHes  the  muscles,  pericranium,  and  skin  over  the  forehead, 
joining  the  sui)raorbital  and  frontal ;  the  latter  runs  iipward  and  back- 
ward over  the  side  of  the  head,  anastomosing  with  its  fellow,  the  occip- 
ital, and  posterior  auricular.  The  temporal  supplies  the  articulation  of 
the  jaw,  the  parotid,  and  the  muscles  in  its. course,  and  gives  off  the 
following-named  branches : 

(a)  The  transverse  facial ^  lying  at  first  between  Stenson's  duct  and  the 
zygoma  upon  the  masseter,  and  accompanied  by  branches  of  the  facial 
nerve.     It  joins  branches  of  facial  and  infraorbital. 

(b)  Middle  temporal^  to  the  muscle,  after  perforating  temporal  fascia, 
grooves  the  squamous  portion,  and  supplies  an  orbital  branch.  It  anas- 
tomoses with  the  deep  temporal. 

(c)  The  anterior  auricular,  two  or  three,  join  branches  of  the  posterior 
auricular  after  supplying  fore  part  of  pinna. 

VIII.  The  internal  maxillary  is  described  in  three  portions — viz. 
maxillary,  pterygoid,  and  spheno-maxillary.  The  first  portion  runs  be- 
tween the  jaw  and  internal  lateral  ligament.  The  second  runs  forward 
and  upward  upon  the  external  pterygoid.  The  third  enters  the  spheno- 
maxillary fossa  between  the  two  roots  of  the  external  pterygoid. 

Branches:  from  the  first  or  maxillary  portion  the  tympanic,  middle 
and  small  meningeal,  inferior  dental ;  from  the  second  or  pterygoid  part 
the  deep  temporal,  pterj^goid,  masseteric,  buccal ;  from  the  third  or  sphe- 
no-maxillary part  the  alveolar,  infraorbital,  superior  or  descending  pala- 
tine, Vidian,  pterygo-palatine,  spheno-palatine. 

(a)  The  tympanic,  through  the  Glaserian  fissure,  joins  the  stylo-mas- 
toid  and  the  tympanic  arteries,  and  supplies  a  deep  auricular  branch. 
(See  Stylo-mastoid  Artery.) 


214  SYSTEMIC  ARTERIES. 

(h)  The  middle  meningeal  ascends  between  the  roots  of  the  auriculo- 
temporal nerve,  through  the  foramen  spinosum,  and  divides  on  entering 
the  cranium  into  an  anterior  and  a  posterior  branch.  These  ramify  on 
the  inner  surface  of  the  calvaria  as  far  as  the  frontal  and  occipital 
bones,  uniting  with  the  posterior  and  anterior  meningeal.  Branches 
pass  to  the  Gasserian  ganglion  and  dura  mater ;  through  the  sphenoidal 
fissure  to  the  orbit ;  and  through  the  hiatus  Fallopii  a  petrosal  branch 
passes  to  join  a  branch  of  the  stylo-mastoid  artery. 

(c)  The  small  menmgeal  enters  the  foramen  ovale,  sometimes  arising 
from  the  preceding. 

{d)  The  inferior  dental  traverses  the  dental  canal,  escaping  at  the 
mental  foramen.  It  sends  forward  an  incisor  branch  in  the  bone,  gives 
off  to  the  groove  a  mylo-hyoid  branch,  and  unites  with  its  fellow  and 
with  the  submental  and  labial  arteries.  It  supplies  the  teeth  by  small 
twigs  to  the  roots  from  below. 

(e)  The  two  deep  tem^poral,  anterior  and  posterior,  join  other  temporal 
branches.  The  anterior  sends  twigs  through  the  malar  bone  to  unite 
with  the  lachrymal. 

(/)  The  pterygoid  branches  supply  the  muscles  of  that  name. 

(g)  The  masseteric  crosses  the  sigmoid  notch  to  the  deep  surface  of  the 
muscle. 

(h)  The  buccal^  on  the  buccinator,  joins  branches  of  the  facial. 

(i)  The  alveolar  sends  branches  through  the  posterior  dental  canals  to 
the  molar  and  bicuspid  teeth,  the  antrum,  and  gums. 

(j)  The  infraorbital  arises  with  the  preceding,  traverses  the  canal, 
supplying  the  orbital  muscular  branches  and  an  anterior  dental,  and,  es- 
caping at  the  infraorbital  foramen,  supplies  the  lachrymal  sac,  sending 
branches  also  over  the  face.  It  joins  branches  of  the  facial  and  oph- 
thalmic arteries. 

(k)  The  descending  (or  superior)  palatine  enters  the  posterior  palatine 
canal,  and  runs  along  the  hard  palate  to  the  anterior  palatine  foramen, — 
thence  through  Stenson's  foramen  to  join  the  naso-palatine  artery.  It 
sends  branches  through  the  accessory  palatine  canals  to  the  soft  palate. 

(?)  The  Vidian,  through  its  canal  to  the  pharynx  and  Eustachian 
tube,  and  gives  a  branch  to  the  tympanum. 

(m)  The  ptery go-palatine,  through  its  canal  to  the  sphenoidal  sinus 
and  pharynx. 

(n)  The  nasal,  or  spheno-palatine,  through  that  foramen  to  the  spongy 
bones,  ethmoidal  cells,  and  antrum.  One  large  branch,  the  artery  of  the 
septum  or  naso-palatine,  unites  with  the  termination  of  the  descending 
palatine  artery. 

Describe  the  internal  carotid  artery. 

This  is  a  very  tortuous  vessel,  and  at  its  origin  is  farther  from  the. 
median  line  than  the  external  carotid,  deriving  the  name  "internal" 
from  its  distribution.  For  description  it  is  divided  into  four  parts :  The 
first,  or  cervical,  extends  from  the  bifurcation  of  the  common  carotid  to 


ARTERIES   OF   THE   HEAB^    ETC.  215 

the  carotid  canal ;  the  second,  or  petrous,  is  in  the  carotid  canal ;  the 
third,  or  cavernous,  runs  in  the  cavernous  sinus ;  and  the  fourth,  or  cere- 
bral, is  the  terminal  portion. 

Cervical  portion^  relations :  in  fronts  skin  and  fasciae,  sterno-mastoid, 
digastric,  and  the  st34oid  process  with  its  muscles ;  external  carotid  artery 
and  its  occipital  and  posterior  auricular  branches;  hypoglossal,  glosso- 
pharyngeal  nerves,  and  pharyngeal  branch  of  vagus;  behind^  rectus 
capitis  anticus  major,  sympathetic  and  superior  laryngeal  nerves ;  exter- 
nally,  internal  jugular  vein  and  vagus,  both  being  in  the  same  sheath 
with  the  artery,  but  having  each  a  separate  investment,  the  nerve  being 
posterior  to,  and  between,  the  artery  and  vein.  Near  the  base  of  the 
skull  the  spinal  accessory,  glosso-pharyngeal,  the  vagus,  and  hypoglossal 
nerves  emerge  between  the  vein  and  artery.  Internally,  pharynx  and 
tonsil,  ascending  pharyngeal  artery,  superior  and  external  laryngeal 
nerves. 

The  petrous  portion  is  at  first  in  front  of  the  tympanum  and  internal 
ear,  and  then  runs  forward  and  inward  to  the  inner  side  of  the  fora- 
men lacerum  medium,  and  ascends,  accompanied  by  the  sympathetic,  to 
the  cavernous  sinus. 

The  cavernous  portion  lies  on  the  floor  of  the  sinus,  surrounded  by  the 
sympathetic,  the  sixth  nerve  being  external. 

The  cerebral  portion  pierces  the  dura  mater  internal  to  the  anterior 
cHnoid  process,  lying  at  the  inner  extremity  of  the  Sylvian  fissure,  be- 
tween the  second  and  third  nerves. 

Name  and  describe  the  branches  of  the  internal  carotid. 

The  first  portion  gives  oiF  no  branches.  The  second  sends  a  tympanic 
branch  through  a  foramen  in  the  carotid  canal.  The  third  gives  ofi"  the 
arterice  receptaculi  to  the  pituitary  gland,  Gasserian  ganglion,  the  cav- 
ernous and  inferior  petrosal  sinuses.  One  of  these  branches  is  the  ante- 
rior meningeal.     It  also  gives  off*  the  ophthalmic.  ^ 

The  ophthalmic  artery  passes  through  the  optic  foramen,  below  and 
external  to  the  nerve,  then  crosses  the  latter,  and  runs  beneath  the  supe- 
rior oblique  muscle  to  the  inner  angle  of  the  eye,  and  divides  into  the 
frontal  and  nasal.  It  gives  off"  two  sets  of  branches — viz.  orbital  and 
ocular.     The  orbital  are  the  following: 

(a)  The  lachrymal  runs  above  the  external  rectus  to  the  gland,  send- 
ing several  malar  branches  through  the  bone  to  the  temporal  fossa  and 
cheek,  a  branch  back  through  the  sphenoidal  fissure  to  join  the  middle 
meningeal,  and  several  to  the  conjunctiva  and  upper  lid  to  join  other 
palpebral  vessels. 

(6)  The  supraorbital,  through  the  notch,  joining  the  temporal  and 
facial  branches. 

(c)  The  ethmoidal  branches,  posterior  and  anterior,  run  through  the 
ethmoidal  canals  to  the  ethmoidal  cells.  The  former  supplies  also  the 
roof  of  the  nose ;  the  latter  runs  with  the  nasal  nerve,  and  divides  into 
a  meningeal  and  a  nasal  branch. 


216  SYSTEMIC  ARTERIES. 

{d)  The  palpebral  branches,  superior  and  inferior,  form  arches  on  the 
lids  between  the  orbicularis  muscle  and  tarsal  cartilages,  the  inferior 
sending  a  branch  to  the  nasal  duct.  Tlicy  anastomose  with  the  orbital 
branch  of  the  temporal  and  with  the  infraorbital  artery. 

(e)  The  frontal^  at  inner  angle  of  the  orbit,  unites  with  the  supra- 
orbital. 

(/)  The  naaal  crosses  the  tendo-oculi  to  lachrymal  sac,  and  gives  off 
the  dorsalis  nasi  branch.     It  joins  the  angular  artery. 

{g)  The  muscular  branches  supply  the  muscles  of  the  eyeball.  They 
are  superior  and  inferior,  and  belong  to  the  ocular  group.  The  other 
ocular  branches  are — 

(h)  The  arteria  centralis  retince,  within  the  optic  nerve  to  retina. 

(i.)  The  ciliary  pierce  the  sclerotic  to  supply  the  iris,  ciliary  body,  and 
choroid.  They  are  derived  from  the  ophthalmic  directly  or  from  some 
of  its  branches,  and  are  divided  into  the  anterior  set,  six  to  eight  in 
number ;  the  short,  ten  to  fifteen ;  and  the  long,  two  in  number. 

The  fourth  portion  of  the  internal  carotid  supplies  the  following 
branches : 

(a)  The  anterior  cerebral,  along  the  front  part  of  the  great  longitu- 
dinal fissure,  and  is  joined,  by  the  anterior  communicating,  with  its  fellow. 
The  two  vessels  then,  side  by  side,  curve  around  the  front  of  the  corpus 
callosum  and  run  back  over  its  upper  surface,  breaking  up  into  terminal 
branches  which  supply  the  anterior  cerebral  lobes,  anterior  locus  per- 
foratus,  and  the  optic  nerves. 

(h)  The  middle  cerebral,  along  the  Sjdvian  fissure  to  the  island  of 
Reil,  supplying  the  pia  mater  over  the  anterior  and  middle  lobes,  as  well 
as  the  anterior  perforated  space. 

(c)  The  posterior  communicating,  running  back  to  join  the  posterior 
cerebral. 

(d )  The  anterior  choroid,  to  descending  horn  of  lateral  ventricle,  send- 
ing branches  to  the  choroid  plexus,  velum,  and  hippocampus  major. 

Describe  the  subclavian  arteries. 

Each  vessel  is  divided  into  three  parts,  the  first  running  to  the  inner 
margin  of  the  scalenus  anticus ;  the  second,  behind  that  muscle ;  the 
third,  from  its  outer  border  to  the  lower  border  of  the  first  rib,  where  it 
becomes  the  axillary  artery.  The  right  and  left  vessels  differ  only  in 
their  first  portions,  the  right  arising  behind  the  sterno-clavicular  joint, 
from  the  innominate ;  the  left,  from  the  aorta  as  a  primary  branch. 

First  Portion  of^  the  Right  Subclavian. — Relations:  in  front,  the 
sterno-mastoid,  hyoid,  and  thyroid  muscles ;  deep  cervical  fascia  ;  inter- 
nal jugular,  vertebral,  and  right  innominate  veins ;  and  superficially,  the 
anterior  jugular  vein,  some  loops  of  the  sympathetic  nerve  and  its  car- 
diac branches,  the  vagus  and  phrenic  nerves ;  behind,  the  transverse 
process  of  the  seventh  cervical  or  first  dorsal  vertebra,  longus  colli,  re- 
current laryngeal,  and  sympathetic  nerve  and  pleura ;  below,  the  pleura 
and  recurrent  nerve. 


AETERIES   OF   THE   HEAD,    ETC.  217 

First  Portion  of  the  Left  Subclavian. — Relations:  in  fronts  the  left 
lung  and  pleura,  left  carotid  artery ;  internal  jugular,  vertebral,  and  left 
innominate  veins ;  vagus,  phrenic,  and  cardiac  nerves ;  and  superficially, 
the  sterno-thyroid,  hyoid,  and  mastoid  muscles;  behind^  sympathetic 
nerve,  oesophagus,  and  thoracic  duct,  the  longus  colli  separating  it  from 
the  spine;  externally.,  pleura;  internally^  trachea,  oesophagus,  and  tho- 
racic duct. 

Second  Portion  of  the  Subclavian, — Relations  :  in  front.,  the  scalenus 
anticus,  phrenic  nerve,  and  the  vein ;  behind  and  below^  pleura. 

Thii'd  Portion. — Relations:  in  front,  the  clavicle,  subclavius,  cervical 
fascia,  suprascapular  artery,  external  jugular,  suprascapular  and  trans- 
verse cervical  veins,  supraclavicular  nerves  from  cervical  plexus,  and 
the  nerve  to  the  subclavius  ;  behind,  the  scalenus  medius ;  above,  omo- 
hyoid, brachial  plexus ;  below ^  first  rib. 

Name  and  describe  the  branches  of  the  subclavian. 

They  are  the  vertebral,  thyroid  axis,  internal  mammary,  and  superior 
intercostal.  They  are  all  derived  from  the  first  portion  on  the  left  side  ; 
on  the  right  the  superior  intercostal  arises  from  the  second  portion. 

I.  The  vertebral  enters  the  transverse  foramen  of  the  sixth  cervical 
Vertebra,  ascends  through  those  of  the  other  cervical  vertebrae,  and, 
grooving  the  upper  border  of  the  atlas  from  without,  backward,  and  in- 
ward, pierces  the  dura  mater.  It  then  ascends  to  the  front  of  the 
medulla  through  the  foramen  magnum,  uniting  at  the  lower  border  of 
the  pons  with  its  fellow  to  form  the  basilar.  The  thoracic  duct  crosses 
the  leftartery.  It  is  at  first  behind  the  internal  jugular  and  its  own 
vein ;  then  between  the  scalenus  anticus  and  longus  colli.  In  the  for- 
amina it  is  accompanied  by  a  sympathetic  plexus,  it  is  in  front  of  the 
spinal  nerves,  and  it  crosses  the  suboccipital  nerve  on  the  atlas. 

Branches:  the  cervical  branches  are  muscular,  to  the  deep  cervical 
region,  joining  the  occipital  and  deep  cervical;'  and  ih^  lateral  spinal^ 
entering  the  intervertebral  foramina. 

The  cranial  branches  include — 

(a)  The  posterior  meningeal,  to  the  falx  cerebelli  and  cerebellar  fossae. 

[b)  The  anterior  spinal,  along  the  front  of  the  medulla,  joins  its  fellow 
to  form  the  upper  part  of  the  anterior  median  artery  of  the  cord.  This 
is  a  small  vessel  which  runs  in  the  anterior  median  fissure  of  the  cord, 
beneath  the  pia  mater,  as  far  as  the  cauda  equina.  It  is  formed  below 
by  offsets  entering  the  intervertebral  foramina,  and  dividing  into  ascend- 
ing and  descending  branches.  It  is  thus  really  a  series  of  short  vessels 
connected  together.  These  branches  are  contributed  by  the  vertebral 
and  ascending  cervical,  intercostal,  lumbar,  ilio-lumbar,  and  lateral  sacral 
from  above  downward. 

(c)  The  posterior ^  spinal  descends  along  the  posterior  nerve-roots  to  the 
Cauda  equina.  It  is  formed  in  a  similar  manner  to  the  anterior,  but  it  is 
bilateral. 

[d )  The  posterior  infenor  cerebellar  divides  under  the  cerebellum  into 


218  SYSTEMIC   AKTERIES. 

two  branches.  The  inner  runs  to  the  notch  between  the  hemispheres ; 
the  outer,  to  their  under  surface  and  the  choroid  plexus  of  the  fourth 
ventricle,  joining  the  superior  cerebellar. 

The  basilar^  formed  by  the  two  vertebrals,  runs  to  the  upper  border 
of  the  pons,  and  divides  into  the  two  posterior  cerebrals,  it  gives  off 
the  following  branches : 

(a)  Several  transverse  arteries  on  each  side.  One,  the  auditory,  enters 
the  internal  meatus ;  another,  the  anterior  inferior  cerebellar^  to  the  ante- 
rior border  of  the  cerebellum. 

(b)  The  superior  cerebellar^  to  upper  surface,  joining  the  inferior  cere- 
bellar. 

(c)  The  posterior  cerebrals^  to  under  surface  of  the  posterior  lobes, 
receiving  the  posterior  communicating.  They  give  off  the  posterior 
choroid  branches  and  supply  the  posterior  perforated  space. 

The  circle  of  Willis  is  an  important  anastomosis,  formed  in  front  by 
the  anterior  cerebrals,  which  are  connected  by  the  short  anterior  com- 
municating artery,  which  is  only  two  lines  in  length,  and  behind  by  the 
two  posterior  cerebrals,  united  to  the  internal  carotid,  close  to  the  origin 
of  the  anterior  cerebrals,  by  the  posterior  communicating  branches.  In- 
cluded in  this  circle  are  the  lamina  cinerea,  the  tuber  cinereum,  the  in- 
fundibulum,  the  corpora  albicantia,  the  optic  commissure,  and  the  pos- 
terior perforated  space. 

II.  The  thyroid  axis,  from  the  fore  part  of  the  subclavian,  divides 
close  to  its  origin  into  the  inferior  thyroid,  suprascapular,  and  transverse 
cervical. 

(1)  The  inferior  thyroid,  to  the  gland  behind  the  sympathetic  and  the 
common  carotid,  joins  its  fellow  and  the  superior  thyroid,  giving  off  the 
following  branches :  ^ 

[a]  Laryngeal,  runs  with  recurrent  nerve ;  [b)  tracheal,  joining  bron- 
chial arteries ;  (c)  oesophageal ;  {d )  muscular,  to  the  inferior  constrictor 
and  hyoid  depressor  muscles  and  the  scaleni ;  and  (e)  the  ascending  cer- 
vical. 

The  last-named  runs  between  the  scalenus  anticus  and  the  rectus 
anticus  major,  joining  the  vertebral  and  giving  other  branches  which, 
with  the  lateral  spinal  of  the  vertebral,  help  form  the  anterior  median 
artery  of  the  cord. 

(2)  The  suprascapular  runs  at  first  between  the  scalenus  anticus  and 
the  sterno-mastoid,  crosses  the  subclavian,  and  runs  behind  the  clavicle 
to  cross  the  transverse  ligament  of  the  scapula.  In  the  supraspinous 
fossa  it  runs  beneath  the  muscle,  which  it  supplies,  and  terminates  in 
the  infraspinatus  where  it  joins  the  dorsal  and  posterior  scapular  artery. 
A  supra-acromial  branch  joins  the  acromio-thoracic  artery;  a  branch 
supplies  the  shoulder-joint,  and  another  the  subscapular  fossa. 

(3)  The  transverse  cervical  divides  at  the  anterior  border  of  the  trape- 
zius into  a  superficial  cervical  branch,  ascending  beneath  and  supplying 
that  muscle,  and  a  posterior  scapidar  running  along  the  posterior  border 
of  the  scapula  to  join  the  subscapular  artery  at  its  inferior  angle. 


ARTERIES   OF   THE   HEAD,    ETC.  219 

III.  The  internal  mammary  descends  from  the  under  surface  of 
the  subclavian  along  the  hinder  surface  of  the  costal  cartilages,  J  inch 
from  the  sternum,  as  far  as  the  sixth  interspace,  and  divides  into  the 
rmisculo-phremc  and  superior  epigastric.  At  first,  behind  the  subclavian 
vein  and  the  phrenic  nerve,  it  lies  against  the  pleura,  but  separated  from 
it  below  by  the  triangularis  sterni. 

Branches :  {a)  Comes  nervi phrenid^  to  the  diaphragm  along  with  the 
nerve,  joins  the  phrenic  arteries. 

{b)  Mediastinal^  to  the  glands  in  the  anterior  mediastinum,  thymus 
gland,  and  areolar  tissue. 

(c)  Pericardiac^  to  upper  part  of  the  pericardium. 

{d)  Sternal^  to  the  bone  and  triangularis  sterni. 

The  four  preceding,  with  the  bronchial  and  intercostal  arteries,  con- 
tribute branches  which  unite  to  form  the  subpleural  mediastinal  plexus. 

(e)  Anterior  intercostal,  to  the  six  upper  spaces,  joining  the  aortic 
branches. 

(/)  Anterior  or  perforating  branches,  through  the  spaces,  and  sup- 
plying the  mammary  gland  and  pectoral  muscles. 

{g)  Musculo-plirenic  pierces  diaphragm  at  eighth  rib  and  runs  behind 
the  cartilages  to  the  last  interspace,  giving  off  the  lower  intercostal 
branches. 

(A)  Superior  epigastric  pierces  sheath  of  the  rectus,  sends  a  branch 
to  join  its  fellow,  and  finally  joins  the  deep  epigastric. 

lY.  The  superior  intercostal  crosses  in  front  of  the  neck  of  the 
first  rib,  and  supplies  the  first  and  part  of  the  second  interspace. 

Its  profunda  cervids  branch  passes  backward  between  the  seventh 
cervical  vertebra  and  the  first  rib,  ascends  under  the  complexus  to  the 
axis,  and  joins  the  princeps  cervicis  and  vertebral  arteries. 

Describe  the  axillary  artery. 

The  continuation  of  the  subclavian  is  called  the  axillary  artery.  It 
extends  from  the  lower  border  of  the  first  rib  to  the  lower  border  of  the 
teres  major  tendon,  and  there  becomes  the  brachial.  It  is  described  in 
three  parts :  the  first,  above  the  pectoralis  minor ;  the  second,  behind  it ; 
and  the  third,  below  it.  ^ 

First  Portion. — Relations:  in  fronts  pectorahs  major,  subclavius,  costo- 
coracoid  membrane,  acromio- thoracic  and  cephalic  veins,  external  anterior 
thoracic  nerve ;  behind^  first  intercostal  muscle,  first  digitation  of  serratus 
magnus,  posterior  thoracic  nerve;  externally^  brachial  plexus;  internally^ 
axillary  vein. 

Second  Part. — In  front,  pectoralis  major  and  minor ;  behind,  subscap- 
ularis;  internally,  vein. 

The  posterior  cord  of  the  plexus  is  behind  it,  the  outer  cord  outside, 
and  the  inner  cord  to  its  inner  side.  The  plexus  thus  surrounds  the  sec- 
ond portion  of  the  artery. 

Third  Part. — In  front,  integument,  fasciae,  pectoralis  major,  median 
nerve,  its  inner  head,  internal  cutaneous  nerve ;  behind,  subscapularis, 


220  SYSTEMIC   ARTERIES. 

tendons  of  latissimus  dorsi  and  teres  major,  musculo-spiral  and  circum- 
flex nerves;  externally^  coraco-brachialis,  musculo-cutaneous,  and  me- 
dian nerves;  internally^  the  vein,  brachial  venge  comites,  ulnar  and 
lesser  internal  cutaneous  nerves. 

Branches:  first  p^rt,  superior  and  acromial  thoracic;  second  part, 
long  and  alar  thoracic ;  third  part,  subscapular  and  circumflex,  poste- 
rior and  anterior. 

(a)  The  superior  thoracic,  between  pectorales  to  side  of  chest,  joins 
the  intercostals. 

(h)  The  acromial  thoracic  divides  into  an  acromial  branch,  to  join  the 
suprascapular ;  a  thoracic,  uniting  with  other  thoracic  branches ;  and  a 
descending,  along  with  the  cephalic  vein,  between-  pectoralis  and  deltoid. 

(c)  The  long  thoracic,  to  pectorales,  serratus,  and  mamma,  joining  the 
intercostal  arteries. 

(d)  The  alar  thoracic,  to  axillary  glands. 

(e)  The  subscapular,  along  the  lower  border  of  the  subscapularis,  join- 
ing branches  with  the  intercostal  and  posterior  scapular  arteries.  Its 
dorsalis  scapulce  branch  passes  through  a  triangle  formed  by  the  two 
teretes  and  the  triceps,  and  divides  into  three  sets — viz.  dorsal,  to  the 
infraspinous  fossa;  ventral,  to  the  subscapular  fossa;  and  descending, 
to  run  between  the  teretes  muscles. 

(/)  The  circumflex  arteries  encircle  the  neck  of  the  humerus.  The  pos- 
terior, with  the  nerve  and  veins,  passes  through,  the  quadrangular  space 
formed  by  the  triceps,  teretes,  and  humerus,  and  ends  in  the  deltoid  and 
shoulder-joint.  It  joins  the  superior  profunda  and  acromial  arteries. 
The  anterior,  beneath  the  biceps  and  coraco-brachialis,  to  end  under  the 
deltoid,  sends  a  twig  to  the  shoulder-joint  along  the  bicipital  groove. 

Describe  the  brachial  artery. 

The  brachial  artery  extends  from  the  end  of  the  axillary,  at  the  lower 
border  of  teres  major,  to  J  an  inch  below  the  elbow-joint,  dividing  into 
the  radial  and  ulnar  arteries.  Relations :  in  front,  integument  and  fascia, 
bicipital  fascia,  median  basilic  vein,  and  median  nerve ;  behind,  triceps, 
coraco-brachialis,  brachialis  anticus,  musculo-spiral  nerve,  and  superior 
profunda  artery ;  externally,  coraco-brachialis,  biceps,  median  nerve ; 
internally,  basilic  vein,  venae  comites,  internal  cutaneous,  ulnar,  and 
median  nerves. 

Name  and  describe  the  branches  of  the  brachial  artery. 

(a)  The  superior  profunda,  along  the  musculo-spiral  groove,  sends  a 
branch  to  the  shoulder-joint,  anastomosing  with  the  circumflex;  the 
posterior  articular  artery,  to  the  back  of  the  elbow,  joining  the  interosse- 
ous recurrent ;  branches  to  muscles ;  and,  finally,  the  continuation  of  the 
vessel  joins  the  radial  recurrent  in  front  of  the  outer  condyle. 

(b)  The  nutrient  artery,  to  the  humerus,  enters  the  foramen. 

(c)  The  inferior  profunda,  on  the  inner  head  of  the  triceps,  accom- 
panies the  ulnar  nerve,  and  divides  into  a  branch  to  the  front  of  the  inner 


ARTERIES   OF   THE    HEAD,    ETC.  221 

condyle  and  another  to  the  back  of  it.  The  former  joins  the  anterior, 
and  the  latter  the  posterior  ulnar  recurrent  artery. 

{d)  The  muscula7'  branches,  to  the  coraco-brachialis,  biceps,  and 
brachiahs  anticus. 

(e)  The  anastomotica  magna  runs  on  the  brachialis  anticus  inward  to 
form  an  arch  with  the  posterior  articular  under  the  triceps.  This  artery 
forms  anastomoses  with  all  the  vessels  around  elbow,  excepting  only  the 
radial  recurrent. 

The  brachial  divides,  about  J  an  inch  below  the  elbow,  into  the  radial 
and  ulnar  arteries. 

Describe  the  radial  artery. 

It  runs  from  the  bifurcation  of  the  brachial  along  the  radial  side  of 
the  forearm  to  the  wrist,  and  winds  back  to  its  posterior  surface.  It 
then  entei-s  the'  palm  through  the  first  dorsal  interosseous,  and  runs 
across  the  hand  to  form  the  deep  palmar  arch  by  joining  the  deep 
branch  of  the  ulnar. 

In  the  forearm,  relations :  in  front,  integument,  fascia,  and  supinator 
longus;  behind,  from  above  downward,  it  lies  on  the  tendon  of  the  biceps, 
supinator  brevis,  pronator  teres,  flexor  sublimis,  flexor  longus  pollicis, 
pronator  quadratus,  and  radius  ;  on  ulnar  side,  flexor  carpi  radialis  and 
pronator  teres ;  on  radial  side,  supinator  longus  and  radial  nerve,  its 
middle  third. 

In  the  wrist  it  lies  on  the  external  lateral  ligament,  scaphoid,  and 
trapezium,  and  is  covered  by  the  extensors  of  the  thumb,  cutaneous 
veins,  and  by  filaments  of  the  radial  and  musculo-cutaneous  nerves. 

In  the  hand  it  Hes  on  the  metacarpal  bones  and  interossei,  covered 
by  the  flexor  tendons,  opponens,  flexor  brevis  minimi  digiti,  and  flexor 
brevis  pollicis. 

Name  and  describe  the  branches  of  the  radial  artery. 

In  the  forearm :  (a)  The  radial  recurrent,  between  the  supinator  longus 
and  the  brachialis  anticus,  joins  superior  profunda. 

(h)  The  muscidar,  to  the  radial  side  of  the  forearm. 

(c)  The  superfidalis  voice,  through  the  muscles  of  the  thumb ;  some- 
times it  ends  in  them,  or  it  may  be  very  large,  or  may  complete  the 
superficial  arch. 

{d)  The  anterior  carpal  runs  inward  to  join  in  the  anterior  carpal  arch 
with  the  ulnar  branch. 

In  the  wrist :  [e)  The  posterior  carpal  joins  the  ulnar  branch,  forming 
the  posterior  carpal  arch.  This  arch  gives  ofi*  the  third  and  fourth  dor- 
sal interosseous  branches. 

(/)  The  metacarpal  runs  on  the  second  dorsal  interosseous  muscle, 
and  joins,  by  branches,  the  first  sup.  perforating  and  palmar  digital 
arteries.  It  divides  into  two  dorsal  digital  branches  for  the  index  and 
middle  fingers,  their  adjacent  sides,  and  it  also  gives  off  an  inferior  per- 
forating artery  to  the  corresponding  palmar  digital. 


222  SYSTEMIC   AKTERIES. 

(ff)  Two  dorsales  poUicis,  along  the  sides  of  the  thumb. 

(h)  The  dorsalis  indicis,  along  the  radial  side  of  the  index  finger. 

In  the  hand  :  (i)  The  princeps  pollfcis,  along  the  ulnar  side  of  the 
first  metacarpal  to  the  first  phalanx,  where  it  divides  into  two  branches 
for  the  palmar  sides  of  the  phalanges. 

(j)  The  radialis  uidicis,  along  radial  border,  palmar  surface  of  index 
finger. 

(k)  The  superior  perforating  arteries  pass  back  between  the  heads  of 
the  last  three  dorsal  interossei  muscles  to  join  the  dorsal  interosseous 
arteries. 

(/)  Three  or  four  palmar  interosseous  branches  join  the  palmar  digital 
arteries  at  the  finger-clefts. 

Describe  the  ulnar  artery. 

The  ulnar  artery  runs  along  the  mner  side  of  the  forearm  to  the  wrist, 
crosses  the  annular  ligament  and  the  palm  of  the  hand,  and  joins  the 
superficialis  volae  to  form  the  superficial  arch. 

In  the  forearm,  relations:  in  front,  integument,  fascia,  and  superficial 
flexor  muscles,  median  nerve,  and  palmar  cutaneous  branch  of  the  ulnar 
nerve ;  behind,  brachialis  anticus,  flexor  profundus  digitorum  ;  idnar  side, 
flexor  carpi  ulnaris,  median  nerve  above  and  ulnar  nerve  below ;  radial 
side,  flexor  sublimis. 

At  the  wrist  the  nerve  is  internal  to  the  artery,  and  the  pisiform  bone 
is  internal  to  the  nerve. 

In  the  hand,  as  the  superficial  arch,  it  is  covered  by^  the  skin,  pal- 
maris  brevis,  and  palmar  fascia.  It  rests  on  the  annular  ligament,  super- 
ficial flexor  tendons,  and  divisions  of  the  median  and  ulnar  nerves. 

Name  and  describe  the  branches  of  the  ulnar  artery. 

Forearm  :  (a)  The  anterior  ulnar  recurrent,  to  front  of  inner  condyle, 
joins  the  anastomotica  magna  and  inferior  profunda. 

(6)  The  posterior  ulnar  recurrent,  beneath  flexor  sublimis  to  back  of 
inner  condyle,  and  between  the  heads  of  the  flexor  carpi  ulnaris  along 
the  ulnar  nerve ;  joins  the  posterior  interosseous  recurrent  and  inferior 
profunda  arteries. 

(c)  The  interosseous,  to  the  upper  border  of  the  interosseous  mem- 
brane, where  it  divides  into  the  anterior  and  posterior  interosseous  arte- 
ries. The  first  runs  on  the  front  of  the  membrane,  which  it  pierces 
above  the  pronator  quadratus,  to  join  the  posterior  branch  and  the 
posterior  carpal  arch.  It  supplies  the  median  artery  to  the  nerve,  mus- 
cular branches,  and  the  nutrient  vessels  of  the  radius  and  ulna.  A 
branch  joins  the  anterior  carpal  arch.  The  posterior  interosseous  de- 
scends along  the  back  of  the  forearm,  between  the  superficial  and  deep 
muscles,  and  joins  the  anterior.  It  gives  off"  the  interosseous  recnrrent, 
which  ascends  beneath  the  anconeus  to  join,  behind  the  olecranon,  in  the 
anastomosis  at  the  elbow-joint. 

{d )  The  muscular^  to  the  ulnar  side  of  the  forearm. 


THE  ABDOMINAL   AORTA   AND   ITS   BRANCHES.  223 

(e)  The  anterior  and  posterior  carpal  join  similar  branches  of  the  radial 
to  form  the  carpal  arches,  the  posterior  giving  a  metacarpal  branch  to 
the  little  finger,  ulnar  side. 

(/)  The  deep  branch  joins  the  radial  to  form  the  deep  palmar  arch, 
Ig)  The  digital,  four,  to  little,  ring,  middle,  and  ulnar  side  of  index 
finger. 

THE  THORACIC   AORTA  AND  ITS  BRANCHES. 
Describe  the  thoracic  aorta. 

The  thoracic  aorta  descends  from  the  lower  border  of  the  fifth  to  the  front 
of  the  last  dorsal  vertebra.  Relations :  in  front,  root  of  left  lung,  peri- 
cardium, and  oesophagus ;  behind,  azygos  minor  vein  and  spinal  column  ; 
to  left,  kft  lung  and  pleura,  and,  below,  oesophagus ;  to  right,  oesophagus 
above,  vena  azygos  major,  thoracic  duct. 

Name  and  describe  the  branches  of  the  thoracic  aorta. 

(a)  The  pericardiac,  to  the  pericardium. 

(b)  The  bronchial,  to  the  bronchial  glands  and  the  oesophagus;  they 
are  also  the  nutrient  vessels  of  the  lung.  The  right  one  arises  from  the 
front  of  the  aorta  together  with  the  left  upper.  The  left  consist  of  an 
upper  and  lower  branch.  The  bronchial  vessels  run  along  back  of  the 
corresponding  bronchus  and  divide  with  the  bronchi,  entering  the  sub- 
stance of  the  lung.  The  right  sometimes  arises  from  the  first  aortic 
intercostal. 

(c)  Four  or  five  oesophageal,  joining  the  inferior  thyroid  above,  the 
gastric  and  phrenic  below. 

{d)  The  posterior  mediastinal,  to  glands  and  areolar  tissue. 

(e)  The  intercostal.  These  are  nine  or  ten,  the  superior  intercostal 
from  the  subclavian  supplying  the  upper  space  or  two.  They  run  under 
the  pleura  and  sympathetic,. the  right  behind  the  oesophagus  and  thoracic 
duct.  They  cross  obliquely  to  the  edge  of  the  rib  above,  running  at  first 
on  the  external,  and  then  between  the  two  sets  of  intercostal  muscles. 

Each  divides  into  two  branches  running  along  the  contiguous  borders 
of  the  two  ribs,  and  each  uniting  anteriorly  with  the  corresponding  branch 
of  the  anterior  intercostals  from  the  internal  mammary.  The  first  joins 
the  superior  intercostal;  the  last  two,  the  lumbar  and  epigastric.  In 
general,  each  lies  between  the  vein  above  and  the  nerve  below. 

A  posterior  branch  runs  from  each,  and  divides  into  a  spinal  branch 
to  the  cord  and  a  muscular  branch. 

THE   ABDOMINAL  AORTA  AND   ITS  BRANCHES. 
Describe  the  abdominal  aorta. 

It  runs  from  the  last  dorsal  to  the  left  side  of  the  middle  of  the  body 
of  the  fourth  lumbar  vertebra,  there  dividing  into  the  two  common  iliacs. 
Relations:  in  front,  lesser  omentum,  stomach,  pancreas,  transverse  duo- 
denum, left  renal  and   splenic  veins,  peritoneum  forming  mesentery, 


224  SYSTEMIC  ARTERIES. 

aortic  and  solar  plexuses ;  behind,  receptaculum  chyli,  thoracic  duct,  left 
lumbar  veins,  and  spine  ^  to  the  right,  crus  of  diaphragm,  vena  cava, 
great  azygos  vein,  thoracic  duct,  right  semilunar  ganglion,  splanchnic 
nerve;  to  left,  splanchnic  nerve,  left  semilunar  ganglion. 

Name  and  describe  its  branches. 

The  parietal  are— I.  The  phrenic,  a  right  and  a  left.  Their  origin 
is  inconstant,  from  the  aorta  separately  or  in  common,  or  from  one  of  its 
branches.  They  run  across  the  crura  to  the  under  surface  of  the  dia- 
phragm, and  each  passes  outward,  behind  the  vena  cava  on  the  right, 
the  oesophagus  on  the  left  side,  and  divides  into  an  internal  branch,  join- 
ing its  fellow  and  the  other  phrenics,  and  an  external,  joining  the  inter- 
costal arteries.  Each  supplies  suprarenal  capsular  branches,  the  right 
sending  branches  to  the  liver  and  vena  cava ;  the  left,  to  the  spleen  and 
oesophagus. 

II.  The  lumbar,  five  on  each  side,  pass  behind  the  psoas  and  sym- 
pathetic, and  divide  into  a  dorsal  branch  to  the  back,  also  sending  twigs 
to  the  spinal  anterior  median  artery  (see  Anterior  Spinal  Branch  of  Ver- 
tehral),  and  an  abdominal  branch  running  between  the  abdominal  mus- 
cles, joining  branches  of  epigastric,  intercostal,  ilio-lumbar,  and  internal 
mammary. 

III.  The  middle  sacral,  along  the  middle  of  the  front  of  the  sacrum 
to  the  coccyx,  joining  the  lateral  sacral  and  entering  Luschka's  gland. 

The  visceral^  branches :  IV.  The  cceliac  axis,  J  inch  long,  divides 
into  the  gastric,  hepatic,  and  splenic.  It  is  covered  by  the  lesser  omen- 
tum, rests  below  on  the  pancreas ;  on  each  side  is  a  semilunar  gangHon, 
and  on  the  right  the  lobus  Spigelii,  on  the  left  ihQ  stomach. 

{a)  The  gastric  artery  runs  to  the  cardiac  orifice,  thence  to  the  right, 
along  lesser  curvature,  in  the  lesser  omentum  as  far  as  the  pylorus.  It 
supplies  both  surfaces  of  the  stomach  and  the  oesophagus,  anastomosing 
with  the  splenic,  hepatic,  and  oesophageal  arteries. 

[b)  The  hepatic  artery  passes  below  the  foramen  of  Winslow  to  the 
pylorus,  then  ascends  in  the  lesser  omentum,  anterior  to  that  foramen, 
to  the  transverse  fissure  of  the  liver,  and  divides  into  a  right  and  a  left 
branch.  Its  pyloric  branch  passes  along  the  lesser  curvature  to  meet  the 
gastric.  Its  cystic  branch  from  the  right  division  ascends  on  neck  of 
the  gall-bladder  and  supplies  it  by  two  branches.  The  other  branch  of 
the  hepatic,  the  gastro-duodenalis,  divides  behind  the  lower  part  of  the 
duodenum  into  a  superior  pancreatico-duodenal  branch,  descending  be- 
tween the  pancreas  and  duodenum  to  join  the  inferior  artery  of  the 
same  name ;  and  the  gastro-epiploica  dextra,  passing  in  tlie  omentum 
toward  the  left,  along  the  great  curvature,  to  meet  the  sinistra. 

(c)  The  splenic  runs  tortuously  to  the  left,  along  the  upper  border  of 
the  pancreas,  and  divides  near  the  spleen  into  branches  which  enter  at 
the  hilus,  some  passing  to  the  stomach. 

Branches  :  Pancreatic,  numerous,  small ;  and  one  larger,  the  pancre- 
atica  magna^  accompanies  the  duct  of  Wirsung. 


PLATE  XVII. 
Fig.  1. — To  face  page  !■ 


O.V. 


Cystic  artery, 


The  Coeliac  Axis  and  its  Branches,  the  liver  having  been  raised  and 
the  lesser  omentum  removed. 


PLATE  XVIII. 
Fig.  2. — To  face  page '. 


to       G^^eat       Oment^^ 


The  Cceliac  Axis  and  its  Branches,  the  stomach  having  been  raised 
and  the  transverse  mesocolon  removed. 


THE   ABDOMINAL   AORTA   AND   ITS   BRANCHES.  225 

Five  to  seven  vasa  brevia,  in  the  gastro-splenic  omentum,  to  great  end 
of  stomach,  joining  the  gastric  and  gastro-epiploic  vessels. 

The  gastro-epiploica  sinistra  runs  to  the  right,  along  the  great  curva- 
ture, to  join  the  dextra. 

y.  The  superior  mesenteric  supplies  the  small  intestine  excQpt 
the  first  part  of  the  duodenum,  as  well  as  the  caecum,  and  ascending 
and  transverse  colon.  Emerging  from  between  the  transverse  duodenum 
and  pancreas,  it  crosses  the  former,  and  descends  in  the  mesentery  to 
the  right  iUac  fossa  with  its  vein  and  a  plexus  of  nerves.  It  ends  by 
anastomosing  with  its  own  ileo-colic  branch.   . 

Branches:  [a]  The  inferior pancreatico-duodenal^  joining  the  superior 
from  the  hepatic  artery. 

[h)  Twelve  to  fifteen  vasa  intestini  tenuis  to  jejunum  and  ileum,  run- 
ning parallel  within  the  mesentery,  each  vessel  bifurcating.  These  di- 
visions, uniting  on  each  side  with  their  fellows,  form  a  series  of  arches 
from  which  are  formed,  similarly,  secondary  arches  until  there  are  four 
or  five  tiers  of  such  arches,  which  progressively  diminish  in  size  as  they 
near  the  gut.  The  terminal  arches  send  numerous  straight  vessels  around 
the  gut. 

(c)  The  ileo-colic  divides  near  the  right  iliac  fossa  into  two  branches. 
The  inferior  joins  the  termination  of  the  superior  mesenteric ;  the  upper 
joins  the  colica  dextra.  It  supplies  the  ileum,  caecum,  appendix,  and 
ascending  colon. 

(c?)  The  colica  dextra,^  to  the  middle  of  the  ascending  colon,  divides 
into  a  lower  branch  joining  the  ileo-colic,  and  an  upper,  which  joins  the 
colica  media.  These  branches  form  arches  from  which  is  supplied  the 
colon. 

[e]  The  colica  media,  to  transverse  colon,  divides  into  a  right  branch 
joining  the  dextra;  a  left,  the  sinistra. 

VI.  The  inferior  mesenteric  supplies  the  descending  colon  and  its 
continuation.  Arising  from  the  left  side  of  the  aorta  an  inch  or  two 
above  the  bifurcation,  it  passes  to  the  left  iliac  fossa,  ending  in  the  pelvis 
as  the  superior  hemorrhoidal.     It  gives  oiF — 

{a)  The  colica  sinistra,  to  the  descending  colon,  dividing  into  an  upper 
branch  joining  the  media ;  a  lower,  the  sigmoid  artery. 

{b)  The  sigmoid,  to  the  flexure,  joins  the  colica  sinistra  above  and  the 
superior  hemorrhoidal  below. 

(c)  T\\Q  superior  hemorrhoidal,  in  the  meso-rectum,  crosses  the  left 
common  iUac  artery  and  vein.  It  divides  into  two  branches,  one  on  each 
side  of  rectum,  which  finally  join  the  middle  and  inferior  hemorrhoidal 
arteries. 

VII.  The  suprarenals,  to  the  under  surface  of  the  suprarenal  cap- 
sules, join  branches  of  phrenic  and  renal  arteries. 

VIII.  The  renal,  to  the  hilus,  enters  by  four  or  five  branches  into 
which  each  vessel  divides  close  to  the  kidney.  They  lie  between  the 
veins  in  front  and  the  ureters  behind.  Branches  pass  to  the  suprarenal 
bodies  and  ureter. 

15— A. 


226  SYSTEMIC   ARTERIES. 

IX.  The  spermatic,  the  ovarian  in  the  female,  to  the  testicles  or 
ovaries  respectively.  Passing  behind  the  peritoneum,  they  cross  the 
ureter  and  psoas,  and  in  front  of  the  vena  cava  on  the  right,  each  cross- 
ing also  the  external  iliac  vessels.  In  the  male  the  vessel  then  runs 
through  the  inguinal  canal  to  the  testis,  joining  the  artery  of  the  vas 
deferens.  In  the  female  it  runs  in  the  broad  ligament  to  the  ovary,  and 
sends  branches  to  the  broad  ligament,  the  tubes,  and  uterus. 

THE  ILIAC  ARTERIES  AND  THEIR  BRANCHES. 
Describe  the  common  iliac  arteries. 

Each  runs  downward  and  outward  from  the  division  of  the  aorta  to 
the  lumbo-sacral  joint,  and  divides  into  the  external  and  internal  iUacs. 

Relations:  each  has  in  front  the  peritoneum,  small  intestine,  ureter, 
and  sympathetic  nerve ;  the  left  is  crossed  by  the  superior  hemorrhoidal 
artery ;  behind  and  to  the  iymer  side  of  each  is  its  vein,  the  right  having 
both  its  own  and  the  left  vein  between  it  and  the  last  lumbar  vertebra, 
and  external  to  each  is  the  psoas  magnus.  The  right  has  also  the  vena 
cava  posteriorly. 

Branches :'  small  twigs  to  the  psoas,  ureters,  and  lymphatic  glands. 

Describe  the  internal  iliac  artery. 

It  descends  to  the  upper  part  of  the  great  sacro-sciatic  foramen,  and 
divides  into  an  anterior  and  a  posterior  trunk. 

Relations:  in  fronts  ureter  and  peritoneum;  behind,  sacrum,  lumbo- 
sacral cord,  companion  vein,  and  the  external  iliac  vein  at  its  upper  part ; 
internally,  the  vein ;  externally,  psoas  muscle. 

Name  and  describe  its  branches. 

The  artery  divides  into  two  main  trunks,  the  anterior  and  posterior. 
The  posterior  gives  off  the  following  branches : 

(a)  The  ilio-lumbar,  dividing  behind  the  psoas  into  an  ihac  and  a 
lumbar  branch.  The  former  supplies  the  iliacus  and  a  nutrient  branch 
to  the  bone.  The  latter  supplies  the  psoas  and  quadratus,  as  well  as 
the  cord,  by  a  spinal  branch  entering  the  last  intervertebral  foramen. 
It  joins  the  last  lumbar  artery. 

(6)  The  lateral  sacral,  upper  and  lower,  unite  with  the  middle 
sacral  artery,  and  also  give  branches  which  enter  the  foramina  supplying 
the  contents  of  the  sacral  canal,  and,  emerging  at  the  posterior  foramina 
to  supply  the  muscles  and  skin  over  the  sacrum,  join  the  sciatic  and 
gluteal  branches. 

(c)  The  gluteal,  through  the  great  sciatic  foramen,  divides  into  a  su- 
perficial and  a  deep  branch.  In  the  pelvis  it  gives  ofi"  muscular  branches 
and  a  nutrient  artery  to  the  ilium. 

The  superficial  branch  breaks  up  into  twigs  which  ramify  in  the  glu- 
teus maximus.  The  deep  subdivides  into  two  others.  Of  these,  one 
runs  along  the  upper  border  of  the  gluteus  minimus  to  the  anterior  su- 


THE   ILIAC  ARTERIES   AND   THEIR   BRANCHES.  227 

perior  spine,  joining  the  circumflex  iliac ;  and  the  lower  branch  passes 
toward  the  great  trochanter,  giving  a  twig  to  the  hip-joint  and  joining 
the  external  circumflex  artery. 

The  anterior  trunk  of  the  internal  ihac  supplies  the  following : 

{d)  The  superior  vesical  represents  the  pervious  part  of  the  foetal 
hypogastric  artery.  It  runs  to  the  apex  and  body  of  the  bladder  and  to 
the  ureter,  joins  its  fellow,  and  gives  ofi"  the  artery  of  the  vas  deferens^ 
which  accompanies  that  structure  to  the  testis.  It  also  generally  gives 
oiF  the  (e)  middle  vesical  to  the  base  of  the  bladder. 

(/)  The  inferior  vesical— vaginal  in  the  female— joins  its  fellow. 
It  supplies  the  bladder,  prostate  gland,  and  seminal  vesicles ;  in  the  fe- 
male, vagina  and  rectum. 

(g)  The  middle  hemorrhoidal  arises  with  the  preceding,  and  runs 
to  the  rectum  to  join  other  hemorrhoidal  arteries. 

(h)  The  uterine  ascends  in  the  broad  ligament  from  the  cervix  along 
the  side  of  the  uterus  and  joins  the  ovarian  artery. 

(i)  The  obturator  runs  forward  below  the  pelvic  brim,  between  the 
peritoneum  and  pelvic  fascia  below  the  nerve,  then  through  the  upper 
part  of  the  obturator  foramen,  dividing  beneath  the  obturator  externus 
into  an  external  and  an  internal  branch.  Skirting  the  edges  of  the  fora- 
men, they  join  below  with  each  other  and  the  internal  circumflex.  The 
external  also  joins  the  sciatic,  and  sends  a  branch  along  the  ligamentum 
teres,  through  the  cotyloid  notch,  to  the  joint. 

In  the  pelvis  an  iliac  branch  to  the  bone  and  iliacus,  a  puhic  branch  to 
the  back  of  the  pubes,  joining  its  fellow  and  the  pubic  of  the  epigastric, 
and  a  vesical  branch,  are  given  off  from  the  main  trunk  of  the  obturator 
artery. 

The  termination  of  the  anterior  trunk  of  the  internal  iliac  then  divides 
into  two  branches,  the  sciatic  and  internal  pudic  arteries. 

(j)  The  internal  pudic  escapes  from  the  pelvis  through  the  great 
sciatic  foramen,  crosses  the  ischial  spine,  and  re-enters  the  pelvis  by  the 
lesser  foramen,  then  runs  along  the  outer  wall  of  the  ischio-rectal  fossa 
an  inch  and  a  half  above  the  tuberosity,  and  upon  the  rami  of  the  ischium 
and  pubes,  to  the  subpubic  arch,  where  it  divides  into  the  artery  of  the 
corpus  cavernosum  and  the  dorsal  artery  of  the  penis. 

This  vessel  is  at  first  in  front  of  the  pyriformis,  the  sacral  plexus  inter- 
vening, and  external  to  the  rectum.  On  the  ischial  spine  it  hes  beneath 
the  gluteus  maximus,  the  pudic  nerve  internally.  In  the  ischio-rectal 
fossa  it  lies  on  the  obturator  internus,  ensheathed  by  the  obturator  fas- 
cia, then  between  the  layers  of  the  perineal  fascia. 

Branches :  (a)  two  or  three  infetior  hemorrhoidal,  to  skin  and  muscles 
around  anus. 

(b)  The  superficial  perineal  runs  over  or  under  the  tranversus  perinei 
to  the  back  of  the  scrotum,  sending  branches  to  the  skin  and  muscles  of 
the  perineum. 

(c)  The  transvefrse  perineal^  to  the  parts  between  the  anus  and  bulb, 
joins  its  lellow. 


228  SYSTEMIC  ARTERIES. 

id)  The  artery  of  the  hulh  runs  in  the  constrictor  urethras,  pierces  the 
bulb,  and  sends  a  branch  to  Cowper's  gland. 

[e)  The  artery  of  the  corpus  cavernosum  runs  forward  in  the  centre  of 
that  body  after  piercing  the  crus  penis. 

(/)  The  dorsal  artery  of  the  penis  runs  between  symphysis  and  crus 
penis,  pierces  the  suspensory  ligament,  and  runs  along  the  dorsum  of 
the  penis  to  glans  and  prepuce.  Here  it  is  superficial,  and  lies  between 
the  median  vein  and  the  corresponding  nerve. 

In  the  female  the  pudic  artery  is  smaller,  but  has  analogous  branches. 
The  superficial  perineal  artery  runs  to  the  labia ;  that  of  the  bulb,  to  the 
bulbus  vestibuli ;  that  of  the  corpus  cavernosum  to  the  corresponding 
part  of  the  clitoris ;  and  the  dorsal  artery  to  the  glans  clitoridis. 

(g)  The  sciatic  accompanies  the  pudic,  resting  on  the  pyriformis 
muscle  and  the  sacral  plexus,  escapes  by  the  great  foramen,  and  de-' 
scends,  midway  between  the  tuber  ischii  and  the  trochanter  major,  with 
the  sciatic  nerves.  It  is  covered  by  the  gluteus  maximus,  and  joins  the 
superior  perforating,  obturator,  and  internal  circumflex  arteries. 

The  branches  are — 

(a)  The  coccygeal,  piercing  the  gi-eat  sciatic  ligament  to  supply  the 
gluteus  maximus  and  the  skin  over  the  sacrum  and  coccyx. 

(6)  The  muscular,  to  the  gluteus  maximus,  joining  the  other  gluteal 
arteries  within  the  substance  of  the  muscle. 

(c)  The  comes  nervi  ischiadici,  in  the  substance  of  the  great  sciatic 
nerve. 

(d)  The  anastomotic,  to  the  muscles  on  the  back  of  the  hip,  anasto- 
mosing with  the  superior  perforating,  internal  circumflex,  and  gluteal 
arteries. 

(e)  The  articular  branches,  to  the  capsule  of  the  hip-joint,  from  the 
above. 

Describe  the  external  iliac  artery. 

It  extends  from  the  division  of  the  common  iliac  to  the  mid-point  be- 
tween the  crest  of  the  pubes  and  the  anterior  superior  spine  of  the  ilium, 
behind  Poupart's  ligament. 

Relations :  in  front,  peritoneum,  subperitoneal  fascia,  sigmoid  flexure 
on  left,  ileum  on  right  side,  lymphatic  vessels  and  glands,  spermatic  or 
ovarian  vessels,  deep  circumflex  iliac  vein,  genital  branch  of  genito- 
crural  nerve  and,  at  times,  ureter ;  behind,  psoas  muscle  and  iliac  fascia 
and  its  vein ;  internally,  its  vein  and  the  vas  deferens ;  externally,  psoas 
and  iliac  fascia. 

Name  and  describe  its  branches. 

(a)  The  deep  epigastric  descends  to  Poupart's  ligament,  then  as- 
cends, internal  to  the  deep  ring,  between  the  transversalis  fascia  and  the 
peritoneum.  It  then  pierces  the  fascia  and  enters  the  sheath  of  the 
rectus,  ascending  on  the  posterior  surface  of  the  muscle,  and  dividing 


ARTERIES   OF   LOWER   EXTREMITY   AND   BRANCHES.      229 

into  branches  which  join  the  superior  epigastric.  The  vas  deferens  in 
the  male,  round  ligament  in  the  female,  cross  the  vessel  on  its  outer  side 
at  the  internal  ring. 

Branches :  the  cremasteric^  to  cord ;  the  pubic,  to  back  of  pubes,  join- 
ing pubic  of  obturator ;  and  the  muscular. 

(b)  The  deep  circumflex  iliac  passes  to  the  anterior  superior  spine 
in  a  sheath  of  the  transversalis  and  iliac  fascia,  thence  along  inner  mar- 
gin of  the  crest,  finally  joining  branches  of  the  gluteal  and  of  the  ilio- 
lumbar arteries  between  the  internal  oblique  and  the  transversalis.  An 
ascending  branch,  between  the  same  two  muscles,  joins  the  deep  epigastric. 

ARTERIES   OF  THE  LOWER  EXTREMITY  AND   THEIR 
BRANCHES. 

Describe  the  femoral  artery. 

It  continues  the  external  iliac  artery  down  into  the  thigh  to  end  at 
the  opening  in  the  adductor  magnus  at  the  junction  of  the  up^er  three- 
fourths  and  lower  one-fourth  of  the  femur.  Its  upper  part  lies  in  Scarpa's 
triangle,  bounded  above  by  Poupart's  ligament,  the  inner  side  formed  by 
the  adductor  longus,  the  outer  by  the  sartorius.  The  lower  part  runs  in 
Hunter's  canal,  a  depression  between  the  vastus  internus  and  the  adduc- 
tores  magnus  and  longus,  covered  by  a  strong  fascia  passing  between 
them. 

Relations:  in  front,  fascia  lata,  crural  sheath,  fascia  covering  Hunter's 
canal,  sartorius,  internal  cutaneous  and  long  saphenous  nerves,  nerve  to 
vastus  internus,  and  filaments  of  the  crural  branch  of  genito-crural  nerve ; 
behind,  psoas  magnus,  pectineus,  adductores  brevis,  longus,  and  magnus, 
femoral  vein  and  profunda  vessels,  branch  of  the  anterior  crural  nerve 
to  pectineus ;  outer  side,  anterior  crural  nerve,  vastus  internus,  and  fem- 
oral vein  below;  inner  side,  sartorius,  adductor  longus,  femoral  vein 
above. 

Name  and  describe  its  branches. 

(a)  The  superficial  epigastric,  through  the  saphenous  opening, 
ascends  in  the  superficial  fascia  over  the  abdomen,  joining  other  epi- 
gastrics. 

(b)  The  superficial  circumflex  iliac,  parallel  with  Poupart's  liga- 
ment to  crest  of  ilium,  joins  deep  circumflex  and  gluteal. 

(c)  The  superior  external  pudic  crosses  to  the  lower  abdomen 
over  the  cord,' supplying  the  penis  and  scrotum  (to  labium  in  female), 
and  joins  the  internal  pudic  terminal*branches. 

(d)  The  inferior  external  pudic  crosses  the  pectineus,  pierces  the 
fascia  lata,  and  supplies  the  perineum  and  scrotum  (labium  in  female), 
joining  the  perineal  arteries. 

(e)  The  muscular  branches  all  along  its  course. 

(/)  The  anastomotica  magna  arises  close  to  the  adductor  open- 
ing, and  divides  into  two  branches :  a  deep,  to  the  inner  side  of  the 


230  SYSTEMIC   ARTERIES. 

knee,  joins  the  recurrent  tibial  and  articular  arteries,  and  a  superficial 
which  runs  with  the  long  saphenous  nerve. 

{g)  The  profunda  artery  arises  from  the  femoral  at  its  outer  and 
back  part,  1  to  2  inches  below  Poupart's  ligament.  It  at  first  runs  out- 
ward, but  afterward  behind  the  femoral,  then  beneath  the  adductor 
longus,  terminating  at  the  lower  third  of  the  thigh  by  piercing  the  ad- 
ductor magnus,  becoming  the  lowest  perforating  artery. 

Relations :  in  front,  adductor  longus,  femoral  and  profunda  veins ; 
behind,  iliacus,  pectineus,  adductol-es  magnus  and  brevis. 
•  Branches:  the  external  circumflex  runs  beneath  the  sartorius  and 
rectus,  and  divides  into — ascending  branches,  under  the  tensor  vaginae  to 
join  the  gluteal  and  deep  circumflex  iliac  arteries ;  descending  branches, 
running  upon  the  vasti,  some  passing  beneath  to  the  knee,  to  join  the 
articular  arteries ;  transverse,  piercing  the  vastus  externus  to  the  back, 
of  the  femur,  and  joining  the  superior  perforating. 

The  intefrnal  circumflex  runs  between  the  psoas  and  pectineus,  and 
supplies  the  adductor  and  obturator  muscles  and  an  articular  twig  to  the 
hip-joint,  under  transverse  ligament.  It  then  joins  in  the  crucial  anas- 
tomosis. 

The  perforating  pierce  the  short  and  great  adductor  muscles  to  the 
back  of  the  thigh,  anastomosing  freely  with  each  other  and  with  the 
popliteal  below.  The  superior  enters  into  the  crucial  anastomosis.  The 
first  arises  above  the  adductor  brevis,  the  second  opposite,  the  third  be- 
low it.  The  second  or  third  gives  the  nutrient  artery  to  the  femur.  The 
termination  of  the  profunda  is  called  the  fourth  perforating. 

Describe  the  popliteal  artery. 

It  runs  from  the  adductor  opening  to  the  lower  border  of  the  poplit- 
eus,  where  it  divides  into  the  anterior  and  posterior  tibial. 

Relations :  in  front,  femur,  ligamentum  posticum,  popliteus ;  behind, 
semimembranosus,  fascia,  gastrocnemius,  plantaris,  and  soleus,  popliteal 
and  short  saphenous  veins,  and  the  internal  popliteal  nerve ;  outer  side, 
external  condyle,  outer  head  of  the  gastrocnemius,  plantaris,  internal 
popliteal  nerve  above ;  inner  side,  inner  condyle,  inner  head  of  the  gas- 
trocnemius, semimembranosus,  popliteal  vein,  and  the  internal  popliteal 
nerve  below. 

Name  and  describe  its  branches. 

[a)  Muscular  superior,  three^or  four,  to  the  lower  part  of  the  ham- 
string muscles  to  join  the  inferior 'perforating ;  inferior  (sural),  to  the 
upper  part  of  the  gastrocnemius,  plantaris,  and  soleus. 

(6)  Cutaneous,  to  the  skin  of  the  calf 

(c)  Articular  superior,  two  in  number,  an  external  and  an  inter- 
nal, wind  around  above  the  condyles  to  the  front.  The  external  gives  a 
branch  to  the  external  vastus  and  one  to  the  joint,  and  also  forms  an 
arch  with  the  anastomotica.     The  internal  gives  a  branch  to  the  internal 


ARTERIES   OF   LOWER   EXTREMITY   AND   BRANCHES.       231 

vastus,  joining  anastoipotica  and  inferior  articular,  and  another  to  the 
knee-joint,  and  also  unites  with  the  inferior  articular. 

(d)  The  azygos  articular  pierces  the  posterior  ligament  to  the 
joint. 

(e)  Articular  inferior  wind  around  the  tibia  below  the  joint.  They 
are  external  and  internal,  and  anastomose  with  the  tibial  recurrent, 
anastomotica,  and  other  articular  branches. 

Describe  the  anterior  tibial  artery. 

It  runs  from  the  lower  border  of  the  popliteus,  between  the  heads  of 
the  tibialis  posticus  and  above  the  interosseous  membrane,  to  the  front 
of  the  leg,  then  descends  as  far  as  the  ankle,  ending  in  the  dorsalis 
pedis. 

Relations :  in  front,  integument,  fasciae,  tibialis  anticus,  extensores 
proprius  poUicis  and  longus  digitorum,  anterior  tibial  nerve ;  behind, 
interosseous  membrane,  tibia,  anterior  tibio-tarsal  ligament ;  outer  side, 
extensores  proprius  pollicis  and  longus  digitorum,  anterior  tibial  nerve ; 
inner  side,  tibialis  anticus,  extensor  proprius  pollicis. 

Name  and  describe  its  branches. 

(a)  The  recurrent  tibial,  through  the  tibialis  anticus  to  the  knee, 
joins  other  articular  arteries. 

(b)  The  muscular,  to  the  muscles  and  skin ;  very  numerous. 

(c)  The  malleolar,  to  the  ankle-joint.  Internal  joins  corresponding 
branches  of  the  posterior  tibial ;  exteimdl  joins  the  tarsal  and  anterior 
peroneal. 

Describe  the  dorsalis  pedis. 

It  is  the  continuation  of  the  anterior  tibial,  and  runs  from  the  bend 
of  the  ankle  to-  the  first  interosseous  space,  where  it  divides  into  the 
dorsalis  allich  and  plantar  digital.  ^ 

Relations:  in  front,  skin,  fascia,  inner  tendon  of  extensor  brevis  digi- 
torum ;  behind,  tarsal  bones  and  their  ligaments ;  tibial  side,  extensor 
proprius ;  fibular  side,  extensor  longus  digitorum,  anterior  tibial  nerve. 

Name  and  describe  its  branches. 

(a)  The  tarsal,  beneath  the  short  extensor,  suppljdng  it  and  the 
tarsus  and  joining  metatarsal  and  peroneal  arteries. 

(b)  The  metatarsal,  over  the  bases  of  the  metatarsal  bones,  joins 
the  tarsal  and  external  plantar,  and  gives  off  three  dorsal  interosseous 
artenes  which  run  in  the  outer  three  intermetatarsal  spaces,  each  di- 
viding opposite  the  metatarso-phalangeal  joint  into  two  dorsal  digital 
branches.  These  arteries  anastomose  at  back  part  of  spaces  with  the 
posterior  perforating,  and  at  front  part  with  the  anterior  perforating. 

(c)  The  dorsalis  allicis  lies  along  the  first  intermetatarsal  space,  and 
supplies  both  sides  of  the  great  toe  and  the  inner  side  of  the  second 
dorsally. 


232  SYSTEMIC   ARTERIES. 

(d)  The  plantar  digital  passes  between  the  heads  of  the  first  dorsal 
interosseous,  joins  with  the  external  plantar  to  form  the  plantar  arch, 
and  after  supplying  inner  side  of  great  toe  divides  into  two  branches  for 
the  adjacent  sides  of  the  great  and  second  toes. 

Describe  the  posterior  tibial  artery. 

It  runs  from  the  lower  border  of  the  popliteus  to  divide,  between 
inner  malleolus  and  heel,  into  the  external  and  internal  plantar  arteries. 

Relations :  in  front,  tibialis  posticus,  flexor  longus  digitorum,  tibia, 
and  ankle-joint;  behind^  skin,  fascia,  gastrocnemius,  soleus,  deep  trans- 
verse fascia,  posterior  tibial  nerve.  This  nerve  is  internal  in  its  upper 
part,  but  lower  down  it  is  external  to  the  artery. 

Name  and  describe  the  branches  of  the  posterior  tibial  artery. 

(a)  The  peroneal  runs  from  1  inch  below  the  popliteus  to  the  lower 
third  of  the  leg,  and  divides  into  the  anterior  and  posterior  peroneal.  It 
is  covered  by  the  soleus  and  deep  transverse  fascia ;  in  front  of  it  are 
the  tibialis  posticus  and  interosseous  membrane ;  external  to  it,  the  fib- 
ula ;  and  externally,  as  well  as  behind,  the  flexor  longus  pollicis. 

The  peroneal  gives  oiF  muscular  branches  and  a  fiutrient  artery  to  the 
fibula.  The  anterior  peroneal  passes  beneath  the  interosseous  membrane 
to  the  front  of  the  leg,  and  runs  to  the  outer  ankle  to  join  the  tarsal 
and  external  malleolar.  The  postenor  peroneal  passes  down  behind  the 
external  malleolus,  and  terminates  in  branches  {external  calcaneal)  which 
anastomose  with  the  external  malleolar. 

(h)  The  nutrient  artery  for  the  tibia,  from  the  posterior  tibial  close 
to  its  origin,  is  the  largest  nutrient  artery  of  bone  in  the  body. 

(c)  The  muscular  branches  to  the  calf-muscles. 

(d)  The  communicating,  crossing  back  of  the  tibia  to  join  the 
peroneal  artery. 

(e)  Several  internal  malleolar,  which  join  the  inner  malleolar  of 
the  anterior  tibial. 

Describe  the  plantar  arteries. 

They  are  the  terminal  branches  of  the  posterior  tibial.  The  internal 
is  at  first  under  cover  of  the  abductor  pollicis,  and  then  between  it  and 
the  flexor  breyis  digjtorum,  anastomosing  at  the  inner  border  of  the 
great  toe  with  its  digital  artery. 

The  external,  the  larger,  passes  to  the  base  of  the  fifth  metatarsal, 
then  to  the  space  between  the  first  and  second  metatarsals,  and  joins  the 
plantar  digital,  from  the  dorsalis  pedis,  to  form  the  plantar  arch. 

Describe  the  plantar  arch. 

^  It  supplies  the  muscles,  fascia,  and  skin  of  the  sole  of  the  foot,  and 
gives  off  the  posterior  perforating.  These  pierce  the  three  outer  spaces 
between  the  heads  of  the  dorsal  interossei  and  join  the  dorsal  interos- 
seous arteries. 


THE   SYSTEMIC   VEINS.  233 

The  digital^  four  in  number,  supply  the  three  outer  toes  and  the  outer 
half  of  the  second  toe :  the  first  runs  to  the  outer  side  of  the  little  toe, 
the  others  bifurcate  to  the  adjacent  sides  of  the  fourth  and  fifth,  fourth 
and  third,  third  and  second  toes^  At  the  point  of  bifurcation  each  sends 
a  small  branch  to  join  the  dorsal  interosseous  arteries  [anterior  per- 
forating). 

THE  VEINS. 

THE  PULMONARY  VEINS. 
Describe  the  pulmonary  veins. 

These  are  four  large  trunks,  two  on  each  side,  which  return  the  blood 
from  the  lungs  to  the  left  auricle.  On  the  right  side  they  pass  behind 
the  right  auricle  and  superior  vena  cava ;  on  the  left,  in  front  of  the 
descending  aorta.  The  upper  right  vein  receives  the  branch  from  the 
middle  lobe. 

THE  SYSTEMIC  VEINS. 

Describe  the  veins  of  the  heart. 

The  great  cardiac  vein  ascends  in  the  anterior  interventricular 
groove  from  the  apex  of  the  heart  to  the  left  auriculo-ventricular 
groove ;  along  this  latter  it  runs  to  the  posterior  surface  of  the  heart, 
to  end  in  the  coronary  sinus.  At  its  termination  it  is  provided  with  a 
valve. 

Three  or  four  posterior  cardiac  veins  ascend  on  the  left  ventricle 
to  the  sinus. 

The  middle  cardiac  vein  ascends  in  the  posterior  interventricular 
groove  to  the  sinus. 

The  right  (small)  coronary  vein  in  the  right  auriculo-ventricular 
groove  to  the  sinus. 

The  coronary  sinus,  1  inch  long,  is  placed  at  the  back  part  of  the 
auriculo-ventricular  groove,  on  the  left  side,  and  opens  into  the  right 
auricle  in  front  of  the  inferior  vena  cava.  Besides  the  foregoing  veins, 
it  receives  the  oblique  vein  of  Marshall,  which  drains  the  back  of  the 
left  auricle.  Its  opening  is  guarded  by  the  Thebesian  valve. 
^  The  other  cardiac  veins  are  several  small  vessels  from  the  front  of  the 
right  ventricle,  the  anterior  cardiac  veins,  opening  directly  into  the 
auricle,  and  the  venae  Thebesii,  in  the  muscular  substance,  which 
open  by  minute  orifices,  the  foramina  Thebesii,  near  the  septum  auricu- 
larum. 

SUPERIOR  VENA  CAVA  AND  INNOMINATE  VEINS. 
Describe  the  superior  vena  cava. 

This  large  trunk  is  formed  by  the  union  of  the  two  venae  innominatae, 
and  returns  the  blood  from  the  head  and  neck,  the  thoracic  walls,  and 


234  THE   SYSTEMIC   VEINS. 

the  upper  extremities.  It  is  about  3  inches  long,  and  descends  from 
the  junction  of  the  first  right  cartilage  with  the  sternum  to  its  termina- 
tion in  the  right  auricle,  opposite  the  upper  border  of  the  third  right 
cartilage. 

At  first  it  is  external  to  the  innominate  artery  and  internal  to  the  right 
phrenic  nerve,  partly  covered  by  the  pleura.  It  then  pierces  the  peri- 
cardium external  to  the  ascending  aorta,  having  descended  in  front  of 
the  right  division  of  the  pulmonary  artery.  It  receives  the  azygos 
major  and  small  pericardiac  and  mediastinal  veins. 

Describe  the  innominate  veins. 

The  innominate  veins,  formed  by  the  union  of  the  subclavian  and  in- 
ternal jugular  of  each  side,  behind  the  inner  end  of  the  clavicle  unite 
to  form  the  superior  vena  cava.  The  right  vein,  1  inch  long,  descends 
vertically  on  the  right  side  of  the  innominate  artery,  while  the  left,  more 
than  2  inches  in  length,  descends  slightly,  running  to  the  right,  behind 
tlie  sterno-hyoid  and  thyroid  muscles  and  upper  part  of  sternum.  The 
transverse  aorta  lies  below  it. 

What  are  the  tributaries  of  the  innominate  veins  ? 

On  each  side  the  vertebral^  inferior  thyroid^  and  internal  mammary 
veins.  The  left  vein  also  receives  the  superior  intercostal  and  some 
small  thymic^  mediastinal,  and  pericardiac  veins  and  the  thoracic  duct, 
while  the  right  is  joined  at  its  origin  by  the  right  lymphatic  duct. 

Describe  the  vertebral  vein. 

This  vein  descends  with  the  artery  through  the  foramina  in  the  trans- 
verse processes  of  the  upper  six  cervical  vertebrae,  crosses  the  subclavian 
artery,  and  opens  into  the  back  part  of  the  vena  innominata. 

It  receives  branches:  from  the  muscles  in  its  course  and  from  the 
spinal  canal  through  the  intervertebral  foramina ;  a  small  vein  which 
accompanies  the  superior  intercostal  artery,  as  well  as  the  anterior  ve)'te- 
hral  and  deep  cervical  veins. 

The  anterior  vertebral  arises  from  the  plexus  over  the  cervical  part  of 
the  spine,  and  runs  along  with  the  ascending  cervical  artery.  The  deep 
cervical  arises  in  the  suboccipital  triangle,  runs  between  the  complexus 
and  semispinalis  and  below  the  transverse  process  of  the  seventh  cervi- 
cal vertebra  to  the  vertebral  vein.  It  receives  branches  from  the  deep 
spinal  muscles,  and  the  occipital  veins  empty  into  it. 

Describe  the  inferior  thyroid  veins. 

These  arise  by  branches  from  the  lateral  lobes  of  the  thjToid  gland, 
and  descend  on  the  trachea  beneath  the  sterno-thyroid  muscles.  They 
anastomose  with  the  superior  and  middle  thyroid  veins,  and  receive 
oesophageal,  laryngeal,  and  tracheal  branches.  The  left  joins  the  in- 
nominate on  its  own  side,  sometimes  in  common  with  the  right.     The 


VEINS   OF   THE   HEAD   AND   NECK.  235 

latter  may  empty  into  the  junction  of  the  two  venae  innominatae  or  join 
the  right  vena  innominata. 

Describe  the  internal  mammary  veins. 

These  are  two  on  each  side,  and  accompany  the  artery,  receiving  cor- 
responding hranchesj  finally  uniting  to  form  a  single  trunk  which  joins 
the  corresponding  innominate. 

Describe  the  superior  intercostal  vein. 

It  drains  the  two  or  three  spaces  below  the  first,  and  enters  on  the 
right  side  the  large  azygos ;  on  the  left  side  it  communicates  with  the 
left  upper  azygos  and  joins  the  innominate. 

VEINS   OF   THE   HEAD  AND  NECK. 

Describe  the  facial  vein. 

The  facial  vein  runs  from  the  inner  angle  of  the  eye  to  the  anterior 
border  of  the  masseter  muscle,  then  backward  below  the  jaw,  joining 
the  anterior  division  of  the  temporo-maxillary  trunk  to  form  the  common 
facial,  which  joins  the  internal  jugular.  It  sends  a  communicating  branch 
along  the  front  of  the  sterno-mastoid  to  the  anterior  jugular.  At  its  ori- 
gin it  is  continuous  with  the  angular^  a  vein  formed  by  the  union  of  the 
frontal  and  supraorbital. 

The  frontal  runs  from  the  forehead,  parallel  with  its  fellow  and  joined 
with  it  by  cross-branches,  to  the  inner  side  of  the  orbit,  and  joins  the 
supraorbital,  which  drains  the  forehead,  eyebrow,  and  upper  lid,  com- 
municating with  the  temporal  and  ophthalmic  veins. 

The  angular  vein  runs  down  and  alongside  of  the  nose  near  its  root. 
It  receives  some  superior  palpebral  and  nasal  veins,  and  communicates 
with  the  ophthalmic,  becoming  continuous  with  the  facial. 

The  facial  vein,  in  addition,  receives  the  following  tributaries : 

Several  inferior  palpebral  veins  communicating  with  the  infraorbital ; 

The  superior  labial  vein  and  small  buccal  and  masseteric  twigs ; 

The  deep  facial  from  the  pterygoid  plexus,  as  well  as  some  parotid 
veins ; 

The  submental^  receiving  the  veins  from  the  lower  lip  and  submaxil- 
lary gland  and  communicating  with  the  anterior  jugular  vein ;  ^ 

The  submaxillary  veins  from  the  gland,  and  the  inferior  palatine  vein 
from  the  plexus  around  the  tonsil  and  soft  palate. 

Describe  the  temporo-maxillary  vein  (posterior  facial). 

This  short  trunk,  formed  by  the  temporal  and  internal  maxillary  veins, 
runs  from  opposite  the  condyle  of  the  lower  jaw  to  the  angle  of  the 
jaw,  and  divides  into  an  anterior  branch  joining  the  facial  and  a  poste- 
rior branch  running  backward  to  form  with  the  posterior  auricular  the 
external  jugular.  This  vein  is  imbedded  in  the  parotid  gland  external 
to  the  external  carotid  artery. 


236  THE  SYSTEMIC  VEINS. 

Describe  the  temporal  vein. 

The  temporal  is  formed  bj^  the  union  of  the  superficial  with  the 
middle  temporal  vein,  and  crosses  over  the  zygoma  and  under  the  paro- 
tid to  join  the  internal  maxillary  vein.  It  receives  the  anterior  amicu- 
lavj  parotid,  and  transverse  facial  veins,  and  tributaries  from  a  plexus 
around  the  articulation  of  the  jaw. 

The  superficial  temporal  arises  from  a  plexus  at  the  side  of  the  head 
from  which  proceed  branches  similar  to  those  of  the  artery.  These  join 
to  form  the  vein. 

^  The  middle  temporal  vein  arises  from  a  plexus  in  the  temporal  fossa, 
pierces  the  fascia  near  the  zygoma,  and  joins  the  above.  This  vein 
receives  an  orbital  branch  and  several  external  palpebral  veins. 

Describe  the  internal  maxillary  vein. 

The  internal  maxillary  vein  arises  from  the  pterygoid  plexus  and 
runs  in  company  with  the  first  part  of  the  artery,  joining  the  temporal 
vein  behind  the  ramus  of  the  jaw. 

The  pterygoid  plexus  corresponds  to  the  second  and  third  parts  of  the 
internal  maxillary  artery.  It  covers  both  pter3^goid  muscles,  and  receives 
veins  corresponding  to  the  branches  of  the  artery — namely,  several  deep 
temporal,^  an  alveolar,  inferior  dental,  two  middle  meningeal,  superior 
palatine,  infraorbital,  and  spheno-palatine,  and  a  communicating  vein 
from  the  inferior  ophthalmic.  The  blood  leaves  by  the  deep  facial  and 
the  internal  maxillary  veins. 

Describe  the  posterior  auricular  and  occipital  veins. 

The  posterior  auricular  vein  descends  over  the  mastoid  process 
and  sterno-mastoid  and  ends  in  the  external  jugular. 

The  occipital  veins,  two  or  three,  join  the  deep  cervical  vein. 

The  emissary  vein  in  the  mastoid  foramen  connects  the  lateral  sinus 
with  the  most  external  of  the  occipital  veins. 

Describe  the  external  jugular  vein. 

It  is  formed  by  the  union  of  the  posterior  auricular  and  the  posterior 
division  of  the  temporo-maxillary  trunk.  It  descends  obliquely  across 
the  sterno-mastoid,  lying  between  the  platysma  and  fascia.  Above  the 
clavicle  it  pierces  the  fascia  and  joins  the  subclavian  at  the  outer  border 
of  the  scalenus  anticus ;  sometimes  it  joins  the  internal  jugular.  It  re- 
ceives the  posterior  external  jugular,  anterior  jugular,  transverse  cervi- 
cal, and  suprascapular  veins.  The  two  latter  correspond  to  the  arteries 
of  the  same  name. 

The  posterior  exteimal  jugular  drains  the  occipital  and  posterior  cervi- 
cal regions. 

The  anterior  jugular  descends  along  the  front  of  the  neck  from  the 
submaxillary  region,  pierces  the  fascia  near  the  inner  end  of  the  clavicle, 
and  joins  the  external  jugular,  sometimes  the  subclavian.  This  vein  and 
its  fellow  are  joined  by  a  cross-branch  just  above  the  sternum,  and  it 


VEINS   OF  THE   HEAD   AND   NECK.  237 

receives  branches  of  communication  from  the  submental,  external  jugu- 
lar, and  facial. 

Describe  the  internal  jugular  vein. 

This  vein  commences  at  the  jugular  foramen  just  below  the  junction 
of  the  inferior  petrosal  with  the  lateral  sinus,  and  descends  with  the  in- 
ternal carotid,  then  with  the  common  carotid,  to  join  at  a  right  angle 
with  the  subclavian  vein  behind  the  clavicle,  thus  forming  the  innomi- 
nate vein.  It  is  placed  external  to  the  carotid  vessels,  lying  in  the 
same  sheath  with  each  in  turn. 

It  receives  the  following  tributaries : 

The  common  facial  {vide  an  tea)  and  the  middle  thyroid. 

The  superior  thyroid^  which  receives  the  superior  laryngeal  and  crico- 
thyroid, and  sometimes  joins  the  common  facial. 

The  pharyngeal  veins.  These  form  a  plexus  on  the  outer  side  of  the 
pharynx,  from  which  several  veins  descend  to  join  the  internal  jugular 
or  common  facial.     Branches  pass  to  join  the  pterygoid  plexus. 

The  lingual  veins.,  including  the  ranine,  dorsal  vein  of  the  tongue.,  and 
the  vence.  comites  of  the  lingual  artery. 

(The  inferior  petrosal  sinus  is  regarded  by  some  anatomists  as  the  first 
tributary. ) 

Describe  the  cerebral  veins. 

These  are  divided  into  two  sets,  the  superficial  and  the  deep. 

Superficial  veins  :  the  superior,  ten  to  twelve  on  each  side,  consist 
of  the  anterior,  middle,  and  posterior  veins  which  run  in  the  sulci,  and, 
joining  with  branches  from  the  mesial  aspect  of  the  brain,  empty  into 
the  superior  longitudinal  sinus.  The  inferior  consist  of  the  middle  cere- 
bral vein,  in  the  Sylvian  fissure,  which  joins  the  cavernous  sinus,  and  the 
great  anastomotic  vein,  in  the  posterior  branch  of  the  same  fissure,  com- 
municating with  the  middle  meningeal  veins  and  joining  the  superior 
petrosal  sinus. 

Deep  veins  :  they  finally  converge  to  two  trunks,  the  vence  Galeni. 
These  run  backward  in  the  velum  interpositum,  the  right  and  left,  lying 
side  by  side,  and  unite  into  the  vena  magna  Galeni.,  which  joins  the 
straight  sinus.  Each  vena  Graleni  is  formed  by  the  union  of  the  choroid 
vein  and  the  vena  corporis  striatic  and  is  joined  by  the  basilar  and  other 
small  veins,  while  the  vena  magna  receives  tributaries  from  the  occipital 
lobes  of  each  side  and  from  the  upper  surface  of  the  cerebellum. 

Describe  the  cerebellar  veins. 

The  superior  join  the  straight  sinus  and  the  vena  magna  internally, 
and  the  superior  petrosal  and  lateral  sinuses  externally. 

The  inferior  enter  the  inferior  petrosal,  lateral,  and  occipital  sinuses 
along  with  branches  from  the  medulla  and  pons. 


238  THE   SYSTEMIC  VEINS. 

Describe  the  cranial  sinuses. 

(1)  The  superior  longitudinal  sinus  is  contained  in  the  upper 
border  of  the  falx  cerebri,  and  extends  from  the  crista  galli  to  the  tor- 
cular  Herophih.  Its  section  is  triangular,  and  its  cavity  is  crossed  by 
several  fibrous  bands,  the  chordae  Willisii,  and  contains  some  Pacchio- 
nian bodies.  It  grooves  the  frontal,  parietal,  and  occipital  bones.  In 
front  a  small  vein  in  the  foramen  caecum  connects  it  with  the  nasal  veins, 
and  through  the  parietal  foramen  it  communicates  with  the  veins  of  the 
scalp.  The  superior  cerebral  veins  open  into  the  sinus,  looking  forward 
contrary  to  the  direction  of  the  blood-current.  At  its  termination  it  en- 
larges and  becomes  continuous  with  the  right  (usually)  or  left  lateral 
sinus.  From  this  dilatation  (the  torcular  Herophili)  a  cross-branch 
passes  to  join  the  straight  sinus. 

(2)  The  inferior  longitudinal  sinus,  in  the  lower  border  of  the 
falx  cerebri,  runs  back  to  join  the  straight  sinus. 

(3)  The  straight  sinus  continues  the  inferior  longitudinal  along  the 
line  of  junction  of  the  falx  with  the  tentorium  backward,  and  joins  the 
lateral  sinus  opposite  to  that  in  which  the  superior  longitudinal  ends. 
It  receives  the  vena  magna  G-aleni,  some  superior  cerebellar  veins,  and  a 
cross-branch  from  the  torcular  Herophili. 

(4)  The  lateral  sinuses  run  in  the  attached  margin  of  the  tento- 
rium from  the  internal  occipital  protuberance  to  the  jugular  foramen, 
grooving,  in  order,  the  occipital,  parietal,  mastoid  portion  of  the  tem- 
poral, and  the  occipital  a  second  time.  Each  sinus  receives  the  supe- 
rior petrosal  sinus  and  emissary  veins  from  the  mastoid  and  posterior 
condylar  foramina,  as  well  as  some  cerebellar,  diploic,  and  posterior 
cerebral  veins. 

(5)  The  occipital  sinus,  small,  sometimes  double,  is  contained  in 
the  falx  cerebelli,  and  opens  into  the  torcular  above  and  the  lateral  sinus 
below  by  a  branch  on  each  side  of  the  foramen  magnum.  It  receives 
some  cerebellar  veins  and  branches  from  the  posterior  spinal  veins. 

(6)  The  cavernous  sinuses,  one  on  each  side  of  the  body  of  the 
sphenoid,  run  from  the  sphenoidal  fissure  to  the  apex  of  the  petrous 
portion  of  the  temporal,  receiving  the  ophthalmic  veins  in  front  and 
joining  the  petrosal  sinuses  behind.  It  receives  the  spheno-parietal 
sinus,  some  inferior  cerebral  veins,  and  is  joined  with  the  opposite 
vessel  by  the  circular  sinus. 

(7)  The  circular  sinus  consists  of  the  anterior  and  posterior  inter- 
cavernous sinuses,  which  join  at  each  end  the  cavernous  sinuses,  thus 
surrounding  the  pituitary  body. 

(8)  The  superior  petrosal  sinus  runs  from  the  cavernous  sinus, 
along  the  upper  border  of  the  petrous  portion  of  the  temporal,  to  end 
in  the  lateral  sinus  at  the  fossa  sigmoidea.  ^  It  receives  the  inferior  cere- 
bral, superior  cerebellar,  and  some  tympanic  veins. 

(9)  The  inferior  petrosal,  in  the  groove  between  the  basilar  process 
and  petrous  portion,  runs  from  the  cavernous  to  join  the  lateral  sinus  at 


VEINS   ON   THE   HEAD   AND   NECK.  239 

the  jugular  foramen,  completing  the  internal  jugular  vein.  (See  under 
Internal  Jugular  Vein, )  it  receives  the  auditory  and  some  inferior  cere- 
bellar veins. 

(10)  The  transverse  (basilar)  sinus  is  a  plexus  in  the  dura  mater 
over  the  basilar  process.  It  joins  the  anterior  spinal  veins  below  and 
the  two  inferior  petrosal  sinuses  laterally. 

Describe  the  ophthalmic  veins. 

The  superior  passes  back  from  the  root  of  the  nose  with  the  oph- 
thalmic artery  through  the  sphenoidal  fissure  to  the  cavernous  sinus. 
At  its  origin  it  connects  with  the  angular  and  supraorbital  veins,  and  - 
receives  the  ethmoidal,^  muscular,,  and  lachrymal ,  vena  centralis  retince^ 
anterior^  and  some  of  the  posterior  ciliary  veins. 

The  inferior  runs  back,  near  the  floor  of  the  orbit,  to  open  into  the 
cavernous  sinus,  sometimes  joining  the  superior.  It  arises  by  the  union 
of  some  muscular  and  posterior  ciliary  veins,  and  is  connected  with  the 
pterygoid  plexus  by  a  branch  through  the  spheno-maxillary  fissure. 

Describe  the  diploic  veins. 

They  run  between  the  tables  of  the  skull  and  open  into  the  dural 
sinuses  or  externally.  The  larger  consist,  on  each  side,  of  a  frontal^ 
through  an  aperture  in  the  supraorbital  notch,  joining  the  supraorbital 
vein  ;  an  occipitaL  to  the  occipital  veins  or  torcular ;  and  two  temporal 
— the  anterior,  through  an  aperture  in  the  great  wing  of  the  sphenoid 
to  join  a  deep  temporal  vein,  and  the  posterior,  through  a  foramen  in 
the  parietal  bone  to  the  lateral  sinus. 

What  are  the  emissary  veins? 

These  small  veins  connect  the  cranial  sinuses  with  the  veins  outside 
by  means  of  foramina  in  the  bones.  These  are  the  principal :  one 
each — 

(a)  Through  mastoid  foramen,  from  lateral  sinus  to  outermost  occip- 
ital vein. 

Q))  Through  posterior  condylar  foramen,  from  lateral  sinus  to  cervical 
venous  plexus. 

(c)  Through  parietal  foramen,  from  superior  longitudinal  to  veins  of 
scalp. 

{d)  Through  a  foramen  in  external  occipital  protuberance  to  occipital, 
veins. 

(e)  Through  foramen  ovale,  from  cavernous  to  pterygoid  plexus. 

(/)  Through  foramen  lacerum  medium,  from  cavernous  sinus  to 
pharyngeal  plexus. 

[g)  Through  carotid  canal,  a  small  plexus  from  cavernous  sinus  to 
internal  jugular. 

Qi)  Through  anterior  condylar  foramen,  a  plexus  from  occipital  sinus 
to  deep  cervical  veins. 


240  THE  SYSTEMIC   VEINS. 

VEINS  OF  THE  UPPER  EXTREMITY. 
Describe  the  superficial  veins. 

They  commence  from  a  plexus  on  the  dorsum  of  the  hand  mostly,  but 
to  some  extent  from  the  palm.     They  comprise  the  following : 

The  ulnar,  anterior  and  posterior^  OQan^y  corresponding  positions  on 
the  inner  side  of  the  forearm,  and  unite  above  in  the  common  ulnar. 

The  radial  vein  is  situated  on  the  outer  side,  and  the  median  as- 
cends mesially,  receives  a  deep  median  vein,  and  divides  at  the  bend  of 
the  elbow  into  the  median  basilic  and  median  cephalic. 

The  median  basilic  joins  the  common  ulnar  to  form  the  basilic. 
The  bicipital  fascia  separates  it  from  the  brachial  artery. 

The  median  cephalic  crosses  the  external  cutaneous  nerve,  and 
joins  the  radial  to  form  the  cephalic. 

The  basilic  runs  along  the  inner  side  of  the  biceps,  pierces  the  fas- 
cia, and  is  continued  upward  into  the  axillary  vein. 

The  cephalic  runs  along  the  outer  side  of  the  biceps,  then  between 
the  pectoralis  major  and  deltoid,  piercing  the  costo-coracoid  membrane 
to  join  the  axillary  vein  below  the  clavicle. 

Describe  the  deep  veins. 

The  deep  veins  of  the  upper  extremity  are  the  vense  comites.  They 
run  one  on  each  side  of  its  artery  from  the  digital  to  the  brachial  arteries. 
The  venae  comites  of  the  latter  vessel,  at  the  lower  border  of  the  sub- 
scapularis  muscle,  empty  into  the  axillary  vein. 

*  The  axillary  vein  runs  internal  to  the  artery,  and  receives  veins  cor- 
responding to  its  branches,  as  well  as  the  cephalic. 

The  subclavian  vein  is  the  continuation  upward  of  the  axillary,  and 
runs,  at  a  lower  level  than  its  artery,  from  which  it  is  separated  by  the 
phrenic  nerve  and  scalenus  anticus,  to  the  inner  border  of  that  muscle,  to 
join  the  internal  jugular,  forming  the  innominate.  It  receives  the  ex- 
ternal jugular^  and  occasionally  the  anterior. 

VEINS  OF  THE  TRUNK. 
Describe  the  azygos  veins. 

The  right  or  vena  azygos  major  commences  by  the  right  ascend- 
ing lumbar  vein.  Ascending  to  the  thorax  through  the  aortic  opening 
and  on  the  bodies  of  the  dorsal  vertebrae  to  the  fourth,  it  arches  over 
the  root  of  the  right  lung  and  joins  the^  superior  vena  cava  above  the 
pericardium.  It  receives  the  right  sup.  intercostal  vein  and  the  remain- 
ing right  intercostal  veins  save  the  firsts  the  left  azygos,  the  right  bron- 
chial, and  some  oesophageal,  posterior  mediastinal,  and  pericardiac  veins. 
Below  it  communicates  with  the  common  iliac  by  means  of  the  ascend- 
ing lumbar. 

The  left  lower  (small)  azygos  vein  commences  as  the  left  ascending 
lumbar,  and  ascends  through  the  left  crus  and  along  the  spine  to  the 


Dura  mater  lining' 
pituitary  fossa. 


Sixth  nerve. 
Internal  carotid. 


PLATE  XIX. 

Fig.  l.^To  face  page  238. 

/'Lining  membrane  of  sinus. 
/Third  nerve. 

/Fourth  nerve. 

/First  division  of  fifth  nerve. 


Plan  showing  the  Relative  Position  of  the  Structures  in  the  Right 
Cavernous  Sinus,  viewed  from  behind. 


Fig.  %— To  face  page  241. 
The  dorsi-spinal  veins. 


Fig.  S.— To  face  page  241. 


Vertical  Section  of  Two  Dorsal  Vertel 
showing  the  Spinal  Veins. 


transverse  Section  of  a  Dorsal  Vertebra, 
showing  the  Spinal  Veins. 


PLATE  XX. 

Fig.  1. — To  face  page  244- 


Portal  Vein  and  its  Branches. 


VEINS   OF   THE   TRUNK.  241 

ninth  dorsal  vertebra.  It  then  crosses  to  the  right,  behind  the  aorta, 
and  joins  the  vena  azygos  major.  It  receives  the  lower  three  or  four 
inter costah  and  some  medtastinal  veins. 

The  left  upper  azygos  vein  is  formed  by  the  fourth  intercostal  to 
the  eighth^  inclusive,  and  joins  the  large  azygos.  It  receives  the  me^z- 
(7.9^^W/ branches,  left  bronchial  vein,  and  communicates  above  with  the 
left  superior  intercostal. 

The  intercostal  veins  lie  above  the  arteries.  The  first  joins  the  innom- 
inate or  vertebral;  the  rest  join  the  azygos  veins,  the  two  or  three 
upper  uniting  to  form  the  superior  intercostal.  They  receive  branches 
from  the  vertebrae  and  the  adjacent  muscles. 

The  bronchial  veins  return  part  of  the  blood  from  the  bronchial  arte- 
ries. The  right  joins  the  vena  azygos  major ;  the  left,  the  left  upper 
azygos. 

Describe  the  spinal  venous  system. 

(a)  The  dorsal  spinal  veins,  from  the  skin  and  muscles,  form  a 
plexus  over  the  arches  of  the  vertebrae,  with  a  median  longitudinal  ves- 
sel over  the  spinous  processes.  Branches  pass  to  the  intercostal,  lumbar, 
and  vertebral  veins. 

(b)  The  venae  basis  vertebrae  run  in  canals  in  the  bodies  of  the 
vertebrae,  and  emerge  by  a  single  or  double  orifice  into  the  spinal  canal 
to  join  the  transverse  branch  which  connects  the  anterior  longitudinal 
veins. 

(c)  The  anterior  longitudinal  spinal  veins  are  two  plexiform 
trunks,  one  on  each  side  of  the  posterior  common  Jigament  throughout 
its  whole  length.  They  are  dilated  opposite  the  bodies,  and  joined  by 
branches  beneath  the  ligament.  Above  they  communicate  with  the 
basilar  sinus.     Branches  also  pass  out  at  the  foramina  on  each  side. 

{(i)  The  posterior  longitudinal  spinal  veins,  one  on  each  side, 
run  between  the  dura  and  the  posterior  wall  of  the  spinal  canal.  Cross- 
branches  join  them,  and  they  communicate  with  the  occipital  sinus  and 
the  dorsal  spinal  veins,  and  with  the  anterior  longitudinal  by  branches 
through  the  same  intervertebral  notches. 

(e)  The  veins  of  the  cord  run  tortuously  in  the  pia  mater,  one 
larger  vein  along  the  anterior  fissure.  They  join  into  several  trunks 
above,  which  empty  into  the  cerebellar  veins  or  the  inferior  petrosal 
sinus. 

Describe  the  inferior  vena  cava. 

This  large  trunk  arises  at  the  fifth  lumbar,  by  the  union  of  the  two 
common  iliacs.  It  ascends  to  the  right  of  the  aorta,  grooves  the  poste- 
rior border  of  the  liver,  pierces  the  diaphragm,  is  enclosed  by  the  serous 
laj^er  of  the  pericardium,  and  empties  into  the  right  auricle.  The  Eu- 
stachian valve  .guards  its  orifice.     It  receives  the  following  tributaries: 

(a)  The  lumbar,  corresponding  to  the  arteries.  Each  arises  by  the 
union  of  an  anterior  branch  from  the  abdominal  wall  and  a  posterior 
16— A, 


242  THE   SYSTEMIC   VEINS. 

from  the  dorsal  plexus,  muscles,  and  spinal  canal.  They  run  inward, 
beneath  the  psoas  muscles,  and  on  the  left  side  behind  the  aorta,  and 
open  into  the  back  of  the  inferior  vena  cava.  Above  and  below,  cross- 
branches  unite  these  veins,  forming  the  ascending  lumbar^  which  is  con- 
tinued up  into  the  azygos  vein.  This  last  also  connects  together  the  ilio- 
lumbar, lateral  sacral,  and  common  iliacs. 

(6)  The  spermatic  forms  within  the  spermatic  cord  a  plexus,  the 
spermatic  or  pampiniform,  which  runs  with  the  spermatic  artery  through 
the  inguinal  canal,  ending  in  several  vessels  uniting  into  a  single  trunk. 
This  vein,  the  spermatic,  ascends  on  the  psoas  behind  the  peritoneum, 
and  joins  the  vena  cava  on  the  right,  the  renal  vein  on  the  left  side. 

In  the  female  its  analogue,  the  ovarian  vein,  forms  the  pampiniform 
plexus  in  the  broad  ligament  and  runs  with  the  artery. 

(c)  The  renal  veins  run  from  the  hilus  of  the  kidney,  in  front  of  the 
arteries,  to  join  the  vena  cava  at  a  right  angle.  The  left  is  longer  and 
crosses  the  aorta.  This  vein  receives  some  small  suprarenal  branches 
and  also  the  spermatic  and  suprarenal  veins. 

{(i)  The  suprarenal  run  from  the  suprarenal  bodies  to  the  vena  cava 
on  the  right,  the  renal  on  the  left  side. 

{e)  The  inferior  phrenic,  two  on  each  side,  run  with  their  arteries. 
The  left  pair  often  joins  the  suprarenal  vein. 

(/)  The  hepatic  veins,  two  or  three,  join  the  vena  cava  at  the 
groove  in  the  liver  through  which  the  latter  passes.  Several  smaller 
veins  empty  separately.  They  return  the  blood  from  the  liver  brought 
by  the  portal  vein  and  the  hepatic  artery. 

Describe  the  common  iliac  veins. 

Formed  by  the  junction  of  the  external  and  internal  iliacs,  they  run 
from  the  base  of  the  sacrum  to  the  upper  part  of  the  fifth  lumbar  ver- 
tebra, and  unite  to  form  the  inferior  vena  cava.  The  right  is  the  shorter, 
and  is  at  first  behind,  later  to  the  right,  of  its  artery,  while  the  left  is 
internal  to  its  own  artery,  then  behind  the  right  iliac  artery.  The  com- 
mon iliacs  receive  the  following  tributaries : 

The  ilio-lumbar,  from  back  of  the  abdomen,  muscles,  and  spinal 
canal,  runs  beneath  the  psoas  to  the  lower  part  of  the  common  iliac.  It 
communicates  with  branches  of  the  lumbar  above,  lateral  sacral  below. 

The  two  middle  sacral,  one  on  each  side  of  the  artery,  anastomose 
with  the  lateral  sacral  and  hemorrhoidal  veins,  and  unite  into  a  single 
vessel  which  joins  the  left  common  iUac  vein. 

VEINS  OF  LOWER  EXTREMITY. 
Describe  the  superficial  veins. 

On  the  dorsum  of  the  foot  is  a  plexus  which  receives  the  digital  veins, 
and  forms  an  arch  from  which  emerge  the  internal  or  long  and  the  ex- 
ternal or  short  saphenous  veins. 

The  long  saphenous,  from  the  inner  part  of  the  plexus,  runs  in 


VEINS   OF   THE   PELVIS.  243 

front  of  the  inner  malleolus,  along  with  the  long  saphenous  nerve,  be- 
hind the  inner  border  of  the  tibia  and  condyle  of  the  femur ;  thence  up 
along  the  antero-internal  part  of  the  thigh  to  join  the  femoral  vein  at 
the  saphenous  opening.  It  communicates  with  the  deep  plantar,  both 
tibial,  and  the  femoral  veins,  and  receives  superficial  plantar  and  cuta- 
neous branches,  and  the  superficial  circurtiflex  iliac,  epigastric^  and  exter- 
nal  pudic  veins. 

The  short  saphenous  vein  ascends  behind  the  outer  malleolus,  and 
external  to  the  tendo  Achillis,  with  the  external  saphenous  nerve,  and 

fierces  the  deep  fascia  in  the  popliteal  space  to  join  the  popliteal  vein, 
t  receives  branches  from  the  heel  and  back  of  the  leg  and  from  the 
deep  veins  and  the  long  saphenous. 

Describe  the  deep  veins. 

The  deep  veins  are  the  veiice  comites  of  the  arteries.  The  posterior 
tibial  veins  receive  the  peroneal,  and  join  the  anterior  tibial  to 
form  the  popliteal.  This  vessel  then  ascends,  crossing  superficial  to 
the  artery,  from  the  inner  to  the  outer  side,  and  becomes  the  femoral  at 
the  adductor  opening.  It  receives  the  external  saphenous  and  veins  cor- 
responding to  the  arterial  branches. 

The  femoral  vein  accompanies  the  artery,  and  becomes  the  external 
iliac  at  Poupart's  hgament.  It  is  at  first  outside,  then  behind,  and  at 
its  termination  internal  to,  the  artery.  It  receives,  in  its  lower  part, 
veins  corresponding  to  the  branches  of  the  superficial  femoral  artery ; 
the  long  saphenous,  and  the  profunda  vein.  The  latter  is  formed  by 
the  union  of  the  vence  comites  of  the  ofisets  of  the  profunda  artery. 

The  external  iliac  runs  to  join  the  internal  iliac  near  the  lumbo- 
sacral articulation,  being  at  first  internal  to,  later  behind,  the  artery.  It 
receives  the  deep  circumflex  iliac,  the  deep  epigastric,  and  a  pubic  vein. 

VEINS  OF   THE  PELVIS. 
Describe  the  internal  iliac  vein. 

It  accompanies  the  artery,  lying  behind  and  to  its  inner  side,  to  join 
the  external  at  the  base  of  the  sacrum,  forming  the  common  iliac.  Its 
tributaries  correspond  to  the  branches  of  the  artery  in  a  general  way. 
Thus,  it  receives  the  following : 

The  gluteal,  sciatic,  and  the  obturator ;  the  lateral  sacral,  which  form 
a  plexus  on  the  sacrum  and  oj)en  into  the  internal  iliac  at  several  points ; 
the  internal  pudic,  which  receives  branches  corresponding  to  the  perineal 
branches  of  the  artery  and  commences  as  the  vein  of  the  corpus  caver- 
nosum. 

The  dorsal  vein  of  the  penis,  at  first  two  veins,  these  uniting  into  one, 
which  runs  back  between  the  two  dorsal  arteries  in  a  median  groove, 
passes  below  the  subpubic  ligament,  and  divides  into  two  veins,  joining 
each  side  of  the  prostatic  plexus,  and  each  division  communicating  with 
the  obturator  and  pudic  veins  of  each  side. 


244  THE  SYSTEMIC   VEINS. 

The  visceral  veins  are  larger  than  the  arteries,  and  communicate  freely 
with  one  another,  so  as  to  form  a  series  of  plexuses,  as  follows : 

The  prostatic  plexus,  continuous  above  with  the  vesical  plexus,  is 
formed  by  the  dorsal  vein  of  the  penis  and  branches  from  the  prostate 
and  its  vicinity.  It  communicates  with  the  radicles  of  the  pudic  vein. 
This  plexus  has  its  analogue  in  the  female  around  the  urethra,  which 
receives  the  dorsal  vein  of  the  clitoris. 

The  vesical  plexus  extends  over  the  body  and  base  of  the  bladder,  and 
communicates  with  the  prostatic  and  hemorrhoidal  plexuses  ;  vaginal  in 
female. 

The  hemorrhoidal  plexus,  in  the  wall  of  the  lower  rectum,  beneath 
the  mucous  coat,  sends  out  superior,  middle,  and  inferior  hemorrhoidal 
veins,  which  follow  the  corresponding  arteries,  and  communicates  freely 
with  the  other  plexuses. 

The  vaginal  plexus  surrounds  the  lower  part  of  the  vagina,  and  com- 
municates with  the  vesical  and  hemorrhoidal  plexuses,  and  the  uterine 
plexus  empties  into  the  ovarian  vein. 

THE  PORTAL   SYSTEM. 
Describe  the  portal  system  of  veins. 

The  portal  vein,  3  inches  long,  arises  from  the  union  of  the  splenic 
and  superior  mesenteric  veins  behind  the  head  of  the  pancreas,  and  as- 
cends behind  the  duodenum  and  between  the  la.yers  of  the  lesser  omen- 
tum. Here  it  runs  behind  hepatic  artery  and  bile-duct.  Accompanied 
by  the  hepatic  plexus  of  nerves  and  lymphatics,  all  enclosed  in  Glisson's 
capsule,  it  then  enters  the  transverse  fissure,  forming  near  the  right 
end  the  "sinus,"  and  divides  into:  a  right  branch,  to  the  right  lobe, 
which  distributes  branches  entering  the  hepatic  substance  with  hepatic 
arterial  branches  and  ducts ;  and  a  left  branch  distributed  like  the  right. 
To  it  are  joined  the  obliterated  umbilical  vein  and  the  ductus  venosus. 

The  vena  portse  receives  the  following  tributaries : 

The  superior  mesenteric,  corresponding  to  the  artery  of  the  same 
name,  receiving  also  the  right  gastro-epiploic  vein,  besides  branches  ac- 
companying those  of  the  artery.     It  joins  the  splenic  vein. 

The  splenic  arises  by  five  or  six  vessels  uniting  after  leaving  the 
hilus,  and  runs  to  the  right  below  the  artery,  joining  the  above  at  a 
right  angle  to  form  the  vena  portae.  It  receives  the  vasa  brevia,  left 
ga,stro-epiploic,  and  pancreatic  branches,  and  sometimes  the  inferior 
mesenteric  vein. 

The  inferior  mesenteric  vein  corresponds  in  branches  and  course 
to  the  artery,  and  empties  into  the  angle  of  junction  of  the  two  pre- 
ceding. 

The  pyloric  runs  with  the  pyloric  branch  of  the  hepatic  artery,  and 
joins  the  vena  portse ;  also  the  vena  coronaria  ventriculi,  running 
with  the  gastric  artery  and  receiving  oesophageal  branches,  joins  the 
vena  portse  above  the  former. 


THE  ABSORBENT  SYSTEM.  245 


THE  ABSORBENT  SYSTEM. 

The  absorbent  system  consists  of  vessels  resembling  thin-walled  veins, 
the  lymphatics^  interrupted  at  intervals  by  the  lymphatic  glands.  The 
lymphatics  of  the  alimentary  canal  are  called  lacteals.  All  these  ves- 
sels converge  to  two  principal  trunks,  the  thoracic  duct  and  the  right 
lymphatic  duct,  which  open  into  the  large  veins  at  the  root  of  the 
neck. 

Describe  the  thoracic  duct  and  right  lymphatic  duct. 

The  former  begins  by  a  dilatation,  the  receptaculum  chyli,  at  the  second 
lumbar  vertebra,  where  the  lacteals  and  lower  lymphatics  unite.  It  is 
placed  behind  or  to  the  right  side  of  the  aorta  at  its  origin,  and  ascends 
between  it  and  the  right  crus  to  the  thorax,  lying  on  the  front  of  the 
dorsal  vertebrae,  between  the  aorta  and  vena  azygos  major.  It  then 
runs  upward  toward  the  left,  behind  the  arch  of  the  aorta  (at  the  fourth 
dorsal  v.),  then  between  the  oesophagus  and  left  subclavian  artery,  and 
at  the  seventh  cervical  vertebra  it  arches  over  the  pleura  to  join  the 
angle  of  union  between  the  left  subclavian  and  internal  jugular  veins. 
It  receives  the  absorbents  from  the  whole  body  excepting  those  of  the 
right  upper  limb  and  right  half  of  the  head,  neck,  chest,  heart,  part 
of  the  upper  surface  of  the  liver  and  right  lung. 

The  right  lymphatic  duct  collects  the  lymph  from  the  parts  just 
mentioned  above.  It  is  only  J  an  inch  or  less  in  length,  and  empties  on 
the  right  side,  at  a  point  corresponding  to  that  where  the  thoracic  duct 
empties  on  the  left  side. 

Describe  the  lymphatics  and  lymphatic  glands  of  the  lower  limb. 

The  lymphatics  are  arranged  in  a  supeijicial  and  a  deep  set.  The  for- 
mer open,  in  general,  into  the  superficial  inguinal  glands ;  the  latter  into 
the  deep  inguinal  glands.  The  superficial  follow,  in  a  general  way,  the 
course  of  the  long  saphenous  vein ;  the  deep  accompany  the  deep  blood- 
vessels, and  in  the  leg  enter  the  popliteal  glands ;  in  the  gluteal  and  ad- 
ductor region  some  enter  the  internal  iliac  glands. 

The  superficial  lymphatics  of  the  lower  part  of  the  trunk  also  join 
the  superficial  inguinal  glands.  The  superficial  lymphatics  of  the  penis 
enter  the  superior  set  of  superficial  inguinal  glands ;  the  deep  run  under 
the  pubic  arch  to  join  the  internal  iliac  glands.  The  superficial  lym- 
phatics of  the  scrotum  join  the  superficial  inguinal  glands.  In  the 
female  external  genitalia  a  similar  disposition  obtains. 

The  superficial  inguinal  glands.,  eight  or  ten,  consist  of  a  superior  or 
oblique  set  in  the  line  of  Poupart's  ligament,  and  an  inferior  or  vertical 
set  lying  around  the  upper  part  of  the  saphenous  vein.  Efferent  vessels 
join  the  deep  inguinal  and  external  ihac  glands. 

The  four  or  five  popliteal  glands  surround  the  vessels,  and  receive  the 
deep  and  some  superficial  absorbents  of  the  leg. 


246  LYMPHATICS. 

The  deep  inguinal  glands  lie  around  the  femoral  vessels ;  one  at  the 
crural  ring  is  constant. 

Describe  the  lymphatics  and  lymphatic  glands  of  the  pelvis  and 
abdomen. 

They  include  the  following : 

Six  or  more  extermd  iliac  glands  surround  these  vessels. 

Numerous  internal  iliac  glands,  and  sacral  glands  on  the  face  of  the 
sacrum. 

The  lymphatics  of  the  bladder  enter  the  internal  iliac  glands  with  the 
prostatic  branches. 

The  lymphatics  of  the  uterm,  with  those  of  the  vagina,  to  the  internal 
iliac  glands. 

The  lymphatics  of  the  rectum  enter  the  sacral  glands. 

The  lumbar  glands  comprise  a  middle  and  two  lateral  groups.  The 
former  lie  around  the  aorta  and  vena  cava,  the  latter  beneath  the  psoas. 
Most  of  the  efferent  vessels  join  to  form,  on  each  side,  the  lumbar  lym- 
phatic trunk,  which  runs  into  beginning  of  thoracic  duct. 

The  lymphatics  of  the  kidney,  deep  and  superficial,  join  the  middle 
lumbar  set  after  receiving  the  suprarenal  lymphatics  and  some  from  the 
ureter. 

The  lymphatics  from  the  testicles,  superficial  and  deep,  through  the 
inguinal  canal,  in  the  cord,  to  join  the  lumbar  glands. 

The  deep  lymphatics  of  the  abdominal  wall  receive  others  from  the 
spinal  canal  and  muscles,  and  join  the  lateral  lumbar  glands.  At  the 
upper  part  they  enter  the  sternal  glands. 

About  one  hundred  and  fifty  mesenteric  glands  lie  between  the  layers 
of  the  mesentery  in  the  arterial  arches  and  around  the  superior  mesen- 
teric artery. 

The  lacteals  form  one  plexus  beneath  the  mucous  membrane  and  one 
in  the  muscular  coat,  and  leave  the  intestine  at  the  attachment  of  the 
mesentery  to  enter  the  mesenteric  glands,  and,  emerging,  join  the  efferent 
vessels  from  the  coeliac  glands  and  form  a  single  trunk.  This  intestinal 
lymphatic  trunk  joins  the  thoracic  duct. 

Sixteen  to  twenty  coeliac  glands,  around  the  coeliac  axis  and  adjacent 
aorta,  receive  the  lymphatics  from  the  stomach,  spleen,  pancreas,  and  a 
krge  part  of  the  liver. 

The  lymphatics  of  the  stomach  traverse  the  gastric  glands  at  the 
greater  and  lesser  curvature  and  join  the  coeliac  glands.  From  the 
left  end  they  join  the  splenic  lymphatics. 

The  lymphatics  of  the  spleen,  superficial  and  deep,  enter  the  coeliac 
glands  after  receiving  the  pancreatic  vessels. 

The  lymphatics  of  the  liver  are  superficial  and  deep.  The  superficial 
on  the  upper  surface  are  arranged  in  four  groups :  (1)  The  mesial,  from 
both  lobes,  run  through  the  diaphragm  to  the  anterior  mediastinal  glands ; 
(2)  the  lateral  of  each  lobe  to  the  coeliac  glands ;  (3)  the  posterior,  through 


THE  ABSORBENT  SYSTEM.  247 

the  diaphragm  to  the  glands  around  the  inferior  vena  cava ;  (4)  an  an- 
terior group  joins  those  on  the  inferior  surface. 

The  superficial  lymphatics  on  the  lower  surface  run  to  the  transverse 
fissure,  for  the  most  part,  to  join  with  the  deep  lymphatics.  Some  join 
the  gastric  lymphatics. 

The  deep  hepatic  lymphatics  accompany  the  portal  and  hepatic  veins. 
The  former  join  the  other  vessels  from  the  under  surface  at  the  transverse 
fissure,  and  traverse  some  small  hepatic  glands  to  join  the  coeliac  glands. 
Those  accompan^^ing  the  hepatic  veins  form  five  or  six  trunks  piercing 
the  diaphragm,  and  join  the  glands  around  the  vena  cava. 

Describe  the  lymphatic  system  of  the  thorax. 

Six  to  ten  internal  mammary  or  sternal  glands  along  the  course  of  the 
vessels. 

Along  the  line  of  the  heads  of  the  ribs,  on  each  side  of  the  spine,  are 
the  ^intercostal  glands.  They  send  vessels  to  both  the  thoracic  and  right 
lymphatic  ducts. 

Several  anteiior  mediastinal  glands  lie  between  the  sternum  and  the 
pericardium. 

Eight  or  ten  superior  mediastinal  or  cardiac^  around  the  great  vessels, 
receive  the  lymphatics  of  the  heart  and  thymus  gland. 

Numerous  bronchial  glands,  between  the  bronchi  and  along  their 
primary  divisions,  receive  the  lymphatics  of  the  lung.  They  deepen 
in  color  as  age  advances. 

Ten  or  twelve  postei^ior  mediastinal^  along  the  oesophagus  and  aorta. 

The  deep  lymphatics  of  the  chest-wall  are  an  anterior  set,  in  the  inter- 
costal spaces,  joining  the  internal  mammary  glands,  and  a  posterior  or 
intercostal  set,  along  with  th'e  intercostal  vessels,  joining  the  intercostal 
glands. 

The  cardiac  lymphatics  run  toward  the  base  of  the  heart,  and  form  a 
trunk  on  each  side.  Of  these,  the  right  enters  a  gland  above  the  aortic 
arch ;  the  left,  the  glands  behind  that  vessel. 

The  pulmonary  lymphatics,  superficial  and  deep,  end  in  the  bronchial 
glands. 

The  oesophageal  lymphatics  form  a  plexus  between  the  muscular  and 
mucous  coats  and  join  the  posterior  mediastinal  glands. 

The  thymic  lymphatics  enter  the  superior  mediastinal  glands. 

Describe  the  lymphatics  of  the  upper  limb. 

They  consist  of  a  superficial  and  a  deep  set,  both  converging  to  the 
axillary  glands.  The  former  have  a  somewhat  similar  distribution  to 
that  of  the  veins,  some  entering  the  infraclavicular  glands ;  the  latter 
correspond  to  the  deep  blood-vessels,  communicate  with  the  superficial 
lymphatics  near  the  wrist,  traverse  the  glands  around  the  brachial  arterj'^ 
near  the  elbow,  and  end  in  the  axillary. 


248  LYMPHATICS. 

Describe  the  axillary  glands. 

They  are  ten  to  twelve  in  number,  and  lie  mostly  along  the  axillary 
vessels,  but  some,  the  pectoral^  subscapular^  and  infraclavicular^  occupy 
the  positions  indicated  by  their  names.  The  efferent  vessels  from  all 
these  glands  run  along  the  subclavian  vein,  and  may  unite  into  a  single 
axillary  lymphatic  trunk.  They  finally  reach  the  thoracic  or  right  lym- 
phatic duct  respectively,  or  they  may  enter  the  subclavian  vein  directly. 

The  superficial  lymphatics  of  the  chest  drain  the  lymph  from  the  pec- 
toral muscles,  skin,  and  mamma,  and  together  with  some  superficial  ab- 
dominal lymphatics,  enter  the  axillary  glands.  Those  from  the  hack 
converge  from  all  parts  to  reach  the  axillary  glands. 

Describe  the  absorbent  system  of  the  head  and  neck. 

One  or  more  suboccipital  glands  on  the  complexus  send  branches  to 
the  cervical  glands. 

Several  mastoid  glands  over  the  insertion  of  the  sterno-mastoid. 

Some  parotid  glands,  beneath  the  parotid  fascia  and  imbedded  in  the 
gland,  receive  superficial  temporal  lymphatics,  and  send  branches  to  the 
submaxillary  and  superficial  cervical  glands. 

The  internal  maxillary  glands,  deep  beneath  the  ramus  of  the  jaw, 
around  the  artery  and  side  of  the  pharynx,  with  branches  to  the  deep 
cervical  glands. 

Eight  or  ten  subma^xillary  glands  beneath  the  base  of  the  jaw  drain 
the  lymph  from  the  floor  of  the  mouth  and  the  salivary  glands  and  from 
the  parotid  lymphatic  glands.  The  efi*erent  vessels  join  the  superficial 
and  deep  cervical  glands. 

The  superfixyial  cervical  glands,  four  to  six,  along  the  external  jugular 
beneath  the  platysma,  receive  the  auricular  lymphatics,  eiFerent  trunks 
from  the  suboccipital,  mastoid,  and  some  from  the  parotid  and  submaxil- 
lary  glands.     The  efferent  vessels  enter  the  inferior  deep  cervical  glands. 

The  deep  cervical,  twenty  to  thirty,  consist  of  an  upper  and  a  lower 
set.  The  former  run  along  the  internal  jugular  vein ;  the  latter  around 
the  lower  part  of  the  vein  and  into  the  supraclavicular  fossa,  and  join 
the  superior  mediastinal  and  axillary  glands ;  they  receive  afferent  trunks 
from  all  the  other  cervical  glands  and  the  lymphatics  of  the  lower  part 
of  the  neck,  and  send  out  branches  which  unite  into  2,  jugular  lymphatic 
trunk.  This  trunk  then  joins  the  thoracic  or  right  lymphatic  duct,  or 
may  open  into  a  large  vein. 

The  lymphatics  of  the  scaTp  join  the  suboccipital,  mastoid,  and  parotid 
glands. 

The  lymphatics  of  the  face  follow  the  course  of  the^  facial  vein  to  the 
submaxillary  glands,  but  there  are  others  externally  which  join  the  parot- 
id glands.  The  deep  lymphatics  from  the  orbit^  nasal  cavity^  palate^ 
and  cheek  join  the  internal  maxillary  glands. 

The  crayiial  lymphatics  form  a  network  in  the  pi  a  mater,  and  run  along 
the  internal  carotid,  vertebral,  and  internal  jugular  veins  to  the  deep 
cervical  glands. 


THE   SPINAL   CORD.  249 

The  lingual  lymphatics  run  with  the  ranine  vein,  traverse  several  lin- 
gual glands,  and  join  the  upper  deep  cervical  glands.  One  or  two  join 
the  submaxillar3\ 


NEUEOLOGY. 

'the  spinal  cord. 

What  are  the  membranes  of  the  spinal  cord  ? 

The  spinal  cord  is  enclosed  by  three  membranes,  the  dura  mater, 
arachnoid,  and  pia  mater. 

Describe  the  dura  mater. 

This  is  a  loose  fibrous  envelope  which  is  attached  closely  to  the  margin 
of  the  foramen  magnum  above,  but  onl}^  loosely  to  the  circumference  of 
the  vertebral  canal  below.  Its  inner  surface  is  covered  by  a  layer  of  epi- 
thelium, and  it  presents  on  each  side  a  series  of  double  orifices  for  the 
exits  of  the  anterior  and  posterior  roots  of  the  spinal  nerves.  The  dura 
is  prolonged  on  to  these  nerves  as  a  tubular  investment. 

Describe  the  arachnoid. 

The  arachnoid  is  a  very  delicate  membrane  which  invests  the  cord  be- 
tween the  dura  and  pia.  It  is  continuous  above  with  the  cerebral  arach- 
noid, and  is  connected  by  meshes  of  fibrous  tissue  with  the  pia,  and  to 
some  extent  also  with  the  dura,  from  which  it  is  separated  by  the  sub- 
dural space.  The  subarachnoid  space  contains  the  subarachnoid  fluid, 
which  separates  it  from  the  pia  mater.  This  space,  by  means  of  the 
foramen  of  Majendie,  is  continuous  with  the  cavity  of  the  ventricles  of 
the  brain. 

Describe  the  pia  mater. 

The  pia  mater  is  closely  connected  to  the  cord,  and  sends  a  prolonga- 
tion down  into  the  anterior,  and  a  very  delicate  process  into  the  posterior 
median  fissure.  It  ensheathes  the  spinal  nerves,  and  ends  below  in  the 
filum  terminale,  which  joins  the  dura  at  the  upper  limit  of  the  sacral 
canal. 

Along  the  anterior  median  surface  of  the  pia  runs  a  prominent  fibrous 
band,  the  linea  splendens^  and  between  the  two  nerve-roots  on  each  side 
is  a  serrated  band,  the  ligamentum  denticulatum^  the  points  of  the  serra- 
tions, about  twenty  on  each  side,  being  attached  to  the  dura  between  the 
pairs  of  nerve-roots. 

Describe  the  spinal  cord. 

It  is  about  18  inches  long,  weighs  an  ounce  and  a  half,  and  occupies 


250  THE   SPINAL   CORD. 

about  the  upper  two-thirds  of  the  spinal  canal —  viz.  from  the  foramen 
magnum  to  the  upper  border  of  the  second  lumbar  vertebra.  It  ends  in 
a  narrow  cord  of  gray  matter  which  runs  in  the  midst  of  the  filum  ter- 
minale. 

What  enlargements  are  found  in  the  spinal  cord? 

The  spinal  cord  presents  two  enlargements — an  upper  or  cervical,  ex- 
tending from  the  third  cervical  to  the  first  or  second  dorsal  vertebra,  and 
a  lower  or  lumbar,  from  the  tenth  dorsal  to  about  the  first  lumbar. 
These  enlargements  correspond  to  the  origin  of  the  nerves  which  supply 
the  upper  and  lower  extremities  respectively.  The  surface  of  the  cord 
presents  several  fissures,  which  will  now  be  described. 

What  are  the  fissures  of  the  cord  ? 

The  anterior  median  fissure  extends  through  about  one-third  the 
thickness  of  the  cord,  as  far  as  the  anterior  white  commissure,  and  con- 
tains a  fold  of  the  pi  a. 

The  posterior  median  fissure  extends  about  halfway  through  its  sub- 
stance to  reach  the  posterior  or  gray  commissure.  It  is  not  a  real  fissure, 
being  filled  up  by  connective  tissue. 

The  antero-lateral  fissure  is  merely  the -line  of  origin  of  the  anterior 
nerve-roots,  while  the  postero-lateral  is  in  reality  a  groove,  and  runs  along 
the  line  of  origin  of  the  posterior  nerve-roots. 

^  Lastly,  a  slight  groove  marks  off"  the  posterior  median  column  on  either 
side  of  the  posterior  median  fissure. 

How  are  the  columns  of  the  cord  formed  ? 

These  fissures  divide  the  cord  into  four  columns  on  each  side. 

The  anterior  column,  between  the  anterior  median  and  antero-lateral 
fissures,  is  continued  above  into  the  pyramid  of  the  medulla.  The  lat- 
eral, between  the  antero-  and  postero-lateral  fissures,  runs  up  to  become 
apparently  the  lateral  column  or  tract  of  the  medulla.  The  posterior 
column,  between  the  postero-lateral  and  posterior  median  fissures,  be- 
comes divided,  by  the  slight  groove  above  mentioned,  into  the  posterior 
lateral  and  posterior  median  columns.  In  the  medulla  the  former  be- 
comes the  funiculus  cuneatus,  the  latter  the  funiculus  gracilis. 

What  is  the  structure  of  the  cord? 

The  spinal  cord  is  composed  of  white  matter  externally  and  of  gray 
matter  within.  The  latter  presents  on  section  the  appearance  of  two 
crescents,  the  horns  looking  outward,  united  across  the  median  line  by 
the  gray  commissure,  which  is  placed  nearer  to  the  apices  of  the  anterior 
than  to  those  of  the  posterior  cornua.  The  posterior  cornua  are  long 
and  narrower  than  the  anterior,  and  extend  almost  to  the  surface  of  the 
cord  at  the  postero-lateral  fissure,  where  they  give  ofi"  the  posterior  nerve- 
roots.     The  anterior  are  blunt  and  do  not  reach  the  surface ;  thus  the 


THE   SPINAL   CORD.  251 

anterior  roots  pierce  the  white  matter  and  emerge  at  the  antero-lateral 
fissure.  The  gray  commissure  is  separated  from  the  anterior  median 
fissure  by  the  anterior  white  commissure,  but  the  posterior  median  fis- 
sure quite  reaches  it. 

Throughout  the  whole  length  of  the  cord  in  the  gray  matter  n-uns  a 
small  central  canal  which  opens  above  into  the  fourth  ventricle  and  en- 
larges below,  at  its  termination.     It  is  lined  by  cylindrical  epithelium. 

The  white  matter  is  composed  of  rnedullated  nerve-fibres  of  varying 
calibre,  held  together  by  a  delicate  reticular  connective  tissue,  the  ncui^- 
oglia^  containing  numerous  neuroglia-cells.  This  neuroglia  sends  in 
septa,  aloiTg  with  which  pass  processes  of  pia  mater,  thus  subdividing 
the  columns  into  smaller  tracts. 

Describe  the  anterior  column. 

The  anterior  column  is  subdivided  into  the  following : 
(1)  On  either  side  of  the  anterior  median  fissure  the  direct  pyramidal 
tracts  forming  above  the  uncrossed  portion  of  the  i^yramids  of  the  me- 
dulla, and  (2)  the  fundamental  fascicidus. 

Describe  the  lateral  column. 

The  lateral  column  is  subdivided  into  (1)  the  mixed  lateral  tract,  next 
to  the  concavity  of  the  gray  substance ;  (2)  the  anterior  radicular  zone, 
somewhat  in  front;  (3)  the  direct  cerebellar  tract,  behind  peripherally; 
and  (4)  the  crossed  pyramidal  tract,  lying  internal  to  the  latter.  Of 
these  the  first  and  second  join  the  lateral  tract  or  column  of  the  medulla, 
the  third  traverses  it  to  reach  the  restiform  body,  and  the  fourth  joins 
the  pyramid  of  the  opposite  side,  forming,  with  its  fellow,  the  decussa- 
tion of  the  pyramids. 

Describe  the  posterior  column. 

The  posterior  column  is  marked  off  into  (1)  the  column  of  Goll,  or 
posterior  median  column,  and  (2)  Burdach's  column,  or  the  posterior 
lateral  column.  The  first  becomes  the  fasciculus  gracilis;  the  second 
enters  the  medulla  under  its  own  name  or  as  the  funiculus  cuneatus. 

Mention  some  points  in  the  structure  of  the  gray  matter. 

The  posterior  cornu  is  constricted  at  its  base  {cervix  cornu),  and  then 
expands  (caput  cornu)  before  narrowing  to  its  extremity  {apex  cornu). 
Around  the  latter  the  neuroglia  forms  the  substantia  gelatinosa. 

The  gray  matter  of  the  cord  consists  of  nerve-fibres,  nerve-cells,  and 
connective  tissue  [neuroglia).  The  nerve-cells  are  for  the  most  part 
arranged  in  columns.  Of  these  columns,  one,  at  the  inner  side  of  the 
cervix  cornu,  is  called  the  posterior  vesicular  column  of  Lockhart  Clarke ; 
a  second,  at  the  concavity  of  the  gray  matter,  the  tractus  intermedio- 
lateralis ;  and  a  third  is  found  along  the  anterior  part  of  the  anterior 


252  THE   BRAIN   OR   ENCEPHALON. 

the;  brain  or  encephalon. 

What  is  the  encephalon? 

The  encephalon  or  brain  is  that  part  of  the  cerebro-spinal  axis  which 
is  contained  in  the  cranium.  It  is  composed  of  the  cerebrum,  cerebel- 
him,  pons  VaroHi,  and  medulla  oblongata. 

What  are  the  membranes  of  the  brain  ? 

They  are  the  dura  mater,  pia  mater,  and  arachnoid. 

Describe  the  dura  mater. 

The  dura  is  similar  in  structure  to  the  dura  of  the  cord,  but  differs 
from  it  in  being  closely  attached  to  the  cranial  bones,  forming,  in  fact, 
their  inner  periosteum.  It  is  continuous  with  that  of  the  cord  at  the 
foramen  magnum,  and  with  the  external  periosteum  of  the  cranial  bones 
by  means  of  its  prolongations  into  the  many  foramina.  It  sends  in 
various  processes  to  support  and  separate  the  different  parts  of  the 
brain,  and  its  layers  separate  to  form  the  cranial  sinuses.  In  the  vicin- 
ity of  the  superior  longitudinal  sinus  are  to  be  found,  on  its  outer  sur- 
face, several  glandulse  Pacchionii.  They  may  also  be  seen  on  its  inner 
surface  and  within  the  sinus,  as  well  as  on  the  pia  mater. 

The  processes  include  the  falces  cerebri  et  cerebelli  and  the  tentorium 
cerebelli. 

The  falx  cerebri  separates  the  cerebral  hemispheres.  In  front  it  is 
narrow,  becoming  broader  behind.  Its  upper  convex  margin  is  attached 
to  the  vault  of  the  cranium  from  the  crista  galli  in  fi'ont  to  the  internal 
occipital  protuberance  behind.  Its  lower  margin  is  free  and  concave  an- 
teriorly, while  it  is  attached  posteriorly  to  the  upper  surface  of  the  ten- 
torium. Above  it  forms  the  superior,  below,  the  inferior  longitudinal 
sinus  and  part  of  the  straight  sinus. 

The  falx  cerebelli  is  triangular,  and  separates,  inferiorly,  the  lateral 
cerebellar  lobes.  It  is  attached  above  to  the  middle  of  the  posterior 
border  of  the  tentorium,  behind  to  the  internal  occipital  crust,  below 
the  torcular  Herophili,  and  to  the  foramen  magnum,  where  it  often 
divides  into  two  parts,  which  are  attached  to*its  margins. 

The  tentorium  covers  the  upper  surface  of  the  cerebellum.  Its  poste* 
rior  border,  where  it  is  attached  to  the  transverse  ridges  of  the  occipital 
bone,  encloses  the  lateral  sinuses ;  along  the  superior  border^  of  the 
petrous  portion  it  forms  the  superior  petrosal  sinus,  and  at  the  junction 
of  its  upper  surface  with  the  falx  cerebri  is  the  straight  sinus.  Besides 
these  points,  it  is  attached  to  the  anterior  and  posterior  clinoid  processes. 
Its  anterior  concave  edge  is  marked  by  an  oval  opening  for  the  crura 
cerebri. 

Describe  the  arachnoid  and  pia  mater. 

The  arachnoid  is  a  similar  membrane  to  that  of  the  cord,  and  is  sepa- 
rated, as  in  the  cord,  by  the  subarachnoid  fluid  from  the  pia.     It  does 


THE  MEDULLA  OBLONGATA.  253 

not  dip  into  the  sulci.  In  front  it  leaves  a  space  between  it  and  the  pia 
mater,  viz.  along  the  pons  and  interpeduncular  region,  the  anterior  sub- 
arachnoidean  space,  and  behind,  between  the  medulla  and  the  cerebellum, 
is  a  second  interval  called  the  posterior  subarachnoidean  space.  Both  are 
connected  with  the  ventricles  of  the  brain  by  the  foramen  of  Magendie 
in  the  pia  mater  covering  the  fourth  ventricle. 

The  subarachnoid  fluid  is  a  clear  alkaline  fluid  containing  1.5  per  cent, 
of  solids,  animal  and  mineral. 

The  pia  mater  is  a  very  vascular,  delicate  membrane  which  dips  into 
the  sulci  and  forms  the  various  choroid  plexuses  and  also  the  velum  of 
the  third  ventricle.  The  vessels  of  the  brain  run  in  the  pia  mater  before 
entering  the  brain. 

Describe  the  medulla  oblongata. 

It  is  a  pyramidal  body,  1  inch  long,  f  inch  wide,  and  i  inch  thick. 
Its  larger  extremity  is  continuous  with  the  pons ;  its  smaller  extremity, 
directed  downward  and  backward,  blends  with  the  spinal  cord.  The  an- 
terior surface  lies  on  the  basilar  groove  of  the  occipital  bone,  and  the 
posterior  in  the  vallecula,  between  the  cerebellar  hemispheres. 

In  front  and  behind  it  is  marked  by  the  continuation  of  the  anterior 
and  posterior  median  fissures  of  the  cord,  the  former,  with  its  process 
of  pia  mater,  ending  in  a  cul-de-sac  just  below  the  pons,  the  foramen 
caecum.     The  posterior  expands  into  the  fourth  ventricle. 

Each  lateral  half  of  the  medulla  is  divided  into  "columns.." 

Describe  each  of  these  "  columns." 

1.  The  pyramid.  This  contains  internally  the  fibres  of  the  crossed 
pyramidal  tract  from  the  lateral  column  of  the  opposite  side  of  the  cord ; 
externally  the  pyramid  contains  the  direct  pyramidal  tract  from  the  an- 
terior column  of  the  cord  of  its  own  side. 

2.  The  lateral  tract  is  the  apparent  continuation  of  the  lateral  column 
of  the  cord.     It  is  very  short,  and  lies  immediately  under  the 

3.  Olivary  body.  This  is  an  oval  mass  of  white  matter  enclosing  the 
corpus  dentatum,  a  gray  nucleus  which  is  hollowed  out  within  and  open 
at  its  upper  part,  admitting  white  fibres.  Above  and  in  front  a  groove 
separates  it  from  the  pons  and  pyramid.  Crossing  it  are  arched  fibres 
which  join  the  restiform  body. 

4.  The  restiform  hody  is  apparently  continuous  with  the  posterior  col- 
umns of  the  cord,  and  diverges  above  from  its  fellow  to  form  the  lateral 
walls  of  the  lower  part  of  the  fourth  ventricle.  It  passes  to  the  cere- 
bellum, together  with  the  direct  cerebellar  tract  of  the  cord. 

Immediately  below  the  restiform  body  from  without  inward  are :  5, 
the  funiculus  of  Rolando;  6,  t\\e  funiculus  cwieatus ;  and  7,  the/ini/cw- 
lus  gracilis  or  the  column  of  Goll  continued  up.  Its  enlarged  extremity, 
the  processus  clavatus,  lies  just  under  the  restiform  body.  The  angle 
of  divergence  from  its  fellow  of  the  opposite  side  is  called  the  calamus 
scriptorius. 


254  THE    BRAIN    OR    ENCEPHALON. 

Mention  some  points  in  regard  to  the  deep  structure  of  the 
medulla. 

Numerous  white  fibres  run  in  the  median  hne,  forming  the  so-called 
septum  of  the  medulla.  Some  of  these  fibres  emerge  from  the  ant.  med. 
fissure  and  cross  the  olivary  body  as  the  arciform  fibres,  which  join  the 
restiform  body.  Most  of  the  remaining  white  fibres  are  the  continuation 
upward  of  the  fundamental  fa^ciculiis^  the  mixed  lateral  tracts  and  the 
anterior  radicular  zone.  (See  Columns  of  the  Cord.)  The  crescentic 
arrangement  of  the  gray  matter  which  obtains  in  the  cord  is  lost  in  the 
medulla.  The  caput  cornu  enlarges  and  appears  close  to  the  surface  as 
the  funiculus  of  Rolando,  which  swells  above  into  the  tubercle  of  Ro- 
lando. The  gray  matter  of  the  base  of  the  posterior  cornu  forms  the 
nucleus  gracilis  in  the  funiculus  gracilis  and  the  nucleus  cuneatus  in  the 
funiculus  cuneatus.  A  part  of  the  base  of  the  anterior  cornu  forms  the 
eminence  of  the  funiculus  teres,  in  which  is  the  hypoglossal  nucleus, 
while  that  part  of  the  cornu  which  is  left  is  known  as  the  formatio 
reticularis. 

Describe  the  pons  Varolii  (tuber  annulare). 

This  part  of  the  brain  serves  to  connect  its  various  divisions.  Situated 
between  the  cerebellar  hemispheres,  it  forms  on  each  side  the  middle  pe- 
duncles of  the  cerebellum,  its  dorsal  surface  forms  the  upper  part  of 
the  floor  of  the  fourth  ventricle.  The  ventral  surface  rests  on  the  sphe- 
noid and  basilar  groove  of  the  occipital  bone,  and  lodges  the  basilar 
artery  in  a  median  furrow,  its  branches  running  in  smaller  lateral  de- 
pressions.    The  pons  is  arched  above,  below,  and  ventrally. 

Describe  the  structure  of  the  pons. 

It  is  made  up  of  nerve-fibres  and  gray  matter.  There  are  two  sets  of 
fibres,  transverse  and  longitudinal^  and  each  set  has  superficial  and  deep 
fibres.  These  four  layers  alternate  with  each  other  from  below  as  fol- 
lows: 1,  superficial  transverse  fibres;  2,  superficial  longitudinal  fibres; 
3,  deep  transverse  fibres;  4,  deep  longitudinal  fibres.  The  first  and 
third  layers  are  prolonged  into  the  middle  peduncles  of  the  cerebellum. 
The  second  layer  is  the  prolongation  upward  of  the  fibres  of  the  pyra- 
mids of  the  medulla.  The  fourth  layer  (immediately  below  the  floor  of 
the  fourth  ventricle)  is  the  upward  prolongation  of  the  fibres  in  the 
" deep  structure "  of  the  medulla.     (See  above.) 

The  gray  matter  occurs  chiefly  as :  1 ,  small  points  (nuclei  pontis)  scat- 
tered amongst  the  fibres ;  2,  the  superior  olivary  nucleus,  situated  behind 
the  third  layer  of  white  fibres  {traxjeziiim). 

Describe  the  cerebrum. 

The  cerebrum  is  the  largest  part  of  the  brain,  and  is  composed  of  two 
symmetrical  halves  separated  by  the  great  longitudinal  fissure.  As  a 
whole  it  is  flattened  below,  convex  above,  broader  behind  than  in  front, 
and  presents  over  its  entire  surface  convoluted  eminences,  the  gyri  or 


LOBES   AND    FISSURES   OF   THE 

convolutions,  separated  by  depressions,  the  sulqr  and  fissures.  The  two  * 
hemispheres  are  connected  by  a  great  transverifee  (White  commissure,  the  u 
corpus  callosum.         ^  ^  .   .  1  <   f- 

The  outer  surface,  including  the  gyri,  is  composed  of  gray  matter,  the  "  j/ 
cortical  substance,  while  the  interior  is  of  whiie  matter.  The  cortical  fi 
layer  is  composed  of  alternate  strata  of  white  ^^gray  matter.  / 

The  sulci  vary  from  \  an  inch  to  1  inch  in  depth.   S^yteral  well-maykod^ 
sulci  divide  the  surface  into  five  lobes.     They  are  the  mlerjobaife  sulci  or 
fissures,  and  include  the  fissure  of  Sylvius,  fissure  of  Rblantlo,  and  the 
parieto-occipital  fissure. 

Describe  the  interlobar  sulci. 

The^sswre  of  S^jhius  runs  outward  from  the  anterior  perforated  space, 
and  divides,  on  the  outer  side  of  the  hemisphere,  into  an  ascending  limb, 
which  runs  upward  and  forward  for  about  an  inch,  and  a  horizontal  limb, 
which  runs  back  between  the  parietal  and  temporo-sphenoidal  lobes. 

l^he.  fissure  of  Rolando  (central  sulcus),  from  its  commencement  (J  inch 
behind  the  mid-point  between  the  glabella  and  external  occipital  protu- 
berance), runs  downward  and  forward,  to  end  a  little  behind  and  above 
the  bifurcation  of  the  Sylvian  fissure. 

T\iQ  parieto-occipital  fissure  commences  at  a  point  midway  between  the 
posterior  extremity  of  the  brain  and  the  fissure  of  Rolando,  and  runs 
downward  and  forward  on  the  mesial  surface  of  the  hemisphere  nearly 
as  far  as  the  corpus  callosum,  and  runs  similarly  also  for  nearly  an  inch 
on  the  convex  surface.  The  first  part  is  well  marked,  and  is  called  the 
internal,  the  second  the  external,  parieto-occipital  fissure. 

Describe  the  lobes  and  fissures  on  the  external  surface  of  the 
cerebrum. 

The  frontal  lobe  lies  in  front  of  the  fissure  of  Rolando,  and  above 
and  in  front  of  the  ascending  limb  of  the  Sylvian  fissure.  It  rests  on 
the  orbital  plate  below. 

The  precentral  fissure  runs  parallel  with  the  lower  part  of  the  fissure 
of  Rolando,  marking  oiF  the  ascending  frontal  convolution^  and  the  part 
in  front  of  it  is  divided  by  the  superior  and  inferior  frontal  sulci,  both 
running  antero-posteriorly,  into  the  superior  or  first,  middle  or  second, 
and  inferior  or  third  frontal  convolutions.  The  last  is  also  called  Broca's 
convolution.  The  under  surface  of  the  frontal  lobe  is  grooved  for  the 
olfactory  tract,  a  sulcus  also  separating  the  lower  part  of  the  first  frontal 
convolution  internally  from  the  continuation  of  the  second  and  third 
externally,  the  latter  two  being  also  separated  by  a  sulcus.  These  gyri 
are  called  respectively  the  internal,  middle,  and  posterior  orbital  con- 
volutions. 

The  parietal  lobe  is  bounded  in  front  by  the  fissure  of  Rolando,  be- 
hind by  the  parieto-occipital,  and  below  by  the  horizontal  part  of  the 
Sylvian  fissure,  which  separates  it  from  the  temporo-sphenoidal  lobe. 

The  intraparietal  fissure  runs  up,  at  first  parallel  to  the  fissure  of 


256  THE   BRAIN   OR   ENCEPHAI.OX. 

Eolando,  then  turns  backward,  separating  the  superior  and  inferior 
parietal  lobules.  It  marks  off  between  it  and  the  fissure  of  Rolando 
the  aficendhig  parietal  convolution.  The  superior  parietal  convolution 
or  lobule  is  continuous  in  front  with  the  ascending  parietal,  and  the  in- 
ferior parietal  lobule  is  subdivided  by  a  vertical  sulcus  into  the  supra- 
marginal  gyrus  in  front  and  the  angular  gyrus  behind.  The  former  is 
continuous  in  front  with  the  superior  temporo-sphenoidal,  and  the  latter, 
behind,  with  the  middle  temporo-sphenoidal  gyrus. 

The  occipital  lobe  is  partly  separated  in  front  from  the  parietal  by 
the  parieto-occipital  fissure,  and  forms,  behind,  the  posterior  extremity 
of  the  hemisphere.  It  is  divided  by  the  superior  and  middle  occipital 
fissures  into  the  superior,  middle,  and  inferior  occipital  convolutions. 
These  are  connected  by  the  annectant  convolutions  with  the  adjacent 
gyri  as  follows:  the  first  annectant  convolution  connects  the  superior 
occipital  with  the  superior  parietal ;  the  second  connects  the  middle 
occipital  with  the  angular ;  the  third  connects  the  middle  occipital  with 
the  middle  temporo-sphenoidal ;  and  the  fourth  joins  the  inferior  occip- 
ital and  inferior  temporo-sphenoidal  convolutions.  The  inferior  occipital 
fissure,  at  the  side  of  the  lobe,  separates  the  inferior  convolution  from  the 
occipito-temporal. 

The  temporo-sphenoidal  lobe  is  bounded  above  and  in  front  by 
the  beginning  of  the  fissure  of  Sylvius  and  its  horizontal  limb;  is  con- 
tinuous behind  with  the  occipital,  and  above  with  the  parietal  lobe.  It 
lies  in  the  middle  fossa  of  the  skull.  The  superior  temporo-sphenoidal 
sulcus,  with  the  middle  and  inferior,  divides  it  into  three  convolutions, 
named,  from  above  downward,  the  first,  second,  and  third  temporo- 
sphenoidal. 

The  central  lobe  (island  of  Reil,  or  insula)  is  triangular,  and  con- 
sists of  five  or  six  convolutions,  the  gyri  operti.  It  lies  in  the  fissure  of 
Sylvius  and  beneath  the  inferior  extremities  of  the  ascending  frontal 
and  ascending  parietal  convolutions,  which,  joined  by  the  inferior  frontal, 
form  the  operculum.  In  front  and  externally  a  deep  sulcus  separates 
it  from  the  orbital  and  frontal  convolutions. 

Describe  the  mesial  and  tentorial  surfaces  of  the  hemisphere. 

The  calcarine  fissure  commences  at  the  back  of  the  hemisphere  by 
two  branches,  and  as  it  runs  forward  is  joined  by  the  internal  parieto- 
occipital fissure,  ending  near  the  back  part  of  the  gyrus  fornicatus.  It 
forms  the  calcar  avis  or  hippocampus  minor  in  the  posterior  horn  of  the 
lateral  ventricle. 

The  calloso-marginal  fissure  runs  from  under  the  front  of  the  corpus 
callosum,  between  the  gyrus  fornicatus  and  the  upper  margin  of  the 
hemisphere,  then  ascends  to  end  in  the  upper  part  of  the  fissure  of 
Rolando  or  close  behind  it. 

The  hippocampal  or  dentate  fissure  runs  from  within  the  back  part  of 
the  gyrus  fornicatus  to  the  hook  of  the  uncinate  gyrus.  It  forms  by  its 
projection  into  the  ventricle  the  hippocampus  major. 


THE    UNDER   SURFACE   OF   THE    ENCEPHALON.  2e57 

The  inteimal  parieto-occipital  fissure  runs  downward  and  forward  to 
join  the  calcarine  fissure. 

The  collateral  or  occipito-temporal  fissure  separates  the  superior  and 
inferior  occipito-temporal  convolutions,  and  forms  the  eminentia  col- 
lateralis.  .  .  .^ 

The  cuneate  or  occipital  lobule  lies  between  the  parieto-occipital  and 
calcarine  fissures. 

The  precuneus  (quadrate  lobule)  lies  between  the  parieto-occipital  and 
the  termination  of  the  calloso-marginal  fissure. 

The  marginal  convolution  is  the  inner  aspect  of  the  first  frontal,  and 
runs  along  the  margin  of  the  longitudinal  fissure  from  the  anterior  per- 
forated space  to  the  calloso-marginal  fissure. 

The  gyrus  fornicatus  runs  from  the  anterior  perforated  space  around 
the  genu  of  the  corpus  callosum,  then  back  along  its  upper  surface, 
around  the  posterior  extremity,  and  lastly,  as  the  gyrus  hippocampi,  runs 
forward  to  end  in  the  uncinate  gyrus.  It  is  bounded  above  by  the 
calloso-marginal  fissure. 

The  uncinate  gyrus  is  the  terminal  part  of  the  preceding.  It  extends 
to  the  fissure  of  Sylvius.  In  front  it  bends  back  in  the  form  of  a  hook, 
the  uncus.  The  under  and  inner  surface  of  the  temporo-sphenoidal  lobe 
presents  two  convolutions  separated  by  the  collateral  fissure.  They  are 
the  lateral  and  median  occipito-temporal,  or,  respectively,  the  fusiform 
and  lingual  convolutions. 

Describe  the  under  surface  of  the  cerebrum. 

It  presents  three  lobes :  the  anterior,  composed  of  the  under  surface 
of  the  frontal,  resting  on  the  orbital  plate ;  a  middle,  composed  of  the 
parietal  and  temporo-sphenoidal ;  and  a  posterior,  the  occipital  lobe. 
The  middle  lies  in  the  middle  fossa,  the  posterior  on  the  upper,  surface 
of  the  tentorium  cerebelli. 

From  before  backward  the  following  parts  come  into  view :  longitu- 
dinal fissure,  corpus  callosum,  lamina  cinerea,  olfactory  bulb  and  tract, 
fissure  of  Sylvius,  anterior  perforated  space,  optic  commissure,  tuber 
cinereum,  infundibulum,  pituitary  body,  corpora  albicantia,  posterior 
perforated  space,  crura  cerebri. 

Describe  each  of  these  parts. 

The  great  longitudinal  ^fissure  completely  separates  the  anterior  and 
posterior  lobes,  but  is  interrupted  between  these  two  points  by  the 
corpus  callosum. 

The  corpus  callosum  is  placed  nearer  the  front  than  the  back  of  the 
hemispheres,  being  convex  from  before  backward  above,  concave  below  ; 
the  fibres  run  transversely,  but  along  the  middle  hne  is  a  longitudinal 
raphe  with  a  white  band  on  each  side,  the  mesial  longitudinal  strice,  and 
near  the  margin  some  lateral  longitudinal  strice. 

The  lamina  cinerea.  is  a  thin  layer  of  gray  matter  lying  between  the 
chiasma  and  the  corpus  callosum,  and  continuous  with  the  gray  matter 
17— A. 


258  THE   BRAIN   OR   ENCEPHALON. 

of  the  anterior  perforated  space  on  each  side.  It  forms  part  of  the 
floor  and  anterior  boundary  of  the  third  ventricle. 

The  olfactory  tract  runs  in  a  groove  close  to  the  great  longitudinal 
fissure  on  the  under  surface  of  the  frontal,  and  ends  in  an  enlarge- 
ment,-the  bulb,  from  which  the  olfactory  nerves  descend  through  the 
cribriform  plate.  Behind,  the  tract  divides  into  two  roots.  The  outer 
runs  back  along  the  margin  of  the  anterior  perforated  space  to  the  Syl- 
vian fissure ;  the  inner  to  the  longitudinal  fissure.  The  triangular  space 
between  the  two  roots  is  occupied  by  gray  matter  forming  part  of  the 
tuber  olfactorium,  which  lies  in  a  depression  on  the  frontal  lobe,  and  is 
composed  internally  of  white  matter. 

The  fissure  of  Sylvius  lodges  the  middle  cerebral  artery.  At  its  inner 
part  is  the  fasciculus  unciformis,  connecting  the  frontal  and  temporo- 
sphenoidal  lobes. 

The  anterior  perforated  space  is  a  triangular  depression  at  the  inner 
side  of  the  Sylvian  fissure,  of  a  grayish  color,  and  is  pierced  by  many 
small  vessels  passing  to  the  corpus  striatum,  under  which  it  lies. 

The  optic  commissure  or  chiasma  (see  Optic  Nerve)  is  formed  by  the 
union  of  the  two  optic  tracts.  It  lies  below  the  lamina  cinerea  and  in 
front  of  the  tuber  cinereum. 

Between  the  optic  tracts  and  the  crura  cerebri  is  a  diamond-shaped 
area,  the  interpeduncular  space.  This  space  includes  the  tuber  cine- 
reum, infundibulum,  pituitary  body,  corpora  albicantia,  and  the  poste- 
rior perforated  space. 

The  tuber  cinereum  is  an  elevation  of  gray  matter  between  the  optic 
tracts  and  corpora  albicantia,  and  forms  part  of  the  floor  of  the  third 
ventricle.  From  its  under  surface  the  infundibulum  runs  down  to  the 
pituitary  body.  The  former  is  hollow  and  of  a  conical  form,  its  cavity 
communicating  with  the  third  ventricle. 

The  pituitary  body.,  or  hypophysis  cerebri^  is  a  reddish-gray  mass  occu- 
pying the  sella  turcica.  Its  weight  is  from  4  to  10  grains.  It  consists  of 
two  lobes,  the  anterior  and  larger  of  which  encloses  the  posterior.  ^  The 
former  is  of  a  yellowish-gray  color ;  the  latter  in  foetal  life  contains  an 
aperture  which  communicates  with  the  infundibulum. 

The  corpora  albicantia  are  two  bodies  placed  behind  the  tuber  cine- 
reum. They  are  composed  of  white  matter,  are  about  the  size  of  a  pea, 
and  contain  each  a  gray  nucleus  which  is  connected  with  its  fellow  across 
the  median  line.  Each  is  formed  by  the  corresponding  anterior  pillar  of 
the  fornix. 

The  posterior  perforated  space  forms  part  of  the  posterior  portion  of 
the  floor  of  the  third  ventricle,  and  is  pierced  by  small  vessels  for  the 
optic  thalami.  It  occupies  the  interval  between  the  corpora  albicantia, 
the  pons,  and  the  crura  cerebri. 

The  crura  cerebri  are  broader  in  front  than  behind  and  less  than  1 
inch  in  length.  They  run  from  the  upper  border  of  the  pons  to  the 
hemispheres  of  the  cerebrum,  under  the  optic  tracts,  which  cross  them. 


THE  LATERAL  VENTRICLES.  259 

The  fourth  nerve  crosses  the  outer  side,  and  the  third  issues  from  the 
inner  side  of  each. 

Each  crus  is  composed  of  two  parts  separated  by  gray  matter,  the 
locus  niger.  The  ventral  part,  or  crusta,  is  a  continuation  of  the  pyram- 
idal fibres  from  the  medulla  and  pons,  while  the  dorsal  part,  or  teg- 
mentuniy  is  the  continuation  of  the  deep  longitudinal  fibres  of  the  pons. 
The  crustae  of  the  two  sides  are  entirely  separate,  but  the  tegmenta  are 
connected  at  the  median  line. 

Describe  the  parts  seen  on  two  horizontal  sections  of  the  cere- 
brum. 

A  section  of  the  hemispheres  about  |  inch  above  the  corpus  callosum 
brings  into  view  the  white  matter  constituting  the  centrum  ovale  minus. 
This  is  dotted  with  the  puncta  vasculosa,  due  to  the  divided  blood-ves- 
sels. A  section  at  the  level  of  the  corpus  callosum  is  called  the  centrum 
ovale  majus  of  Vieussens. 

The  anterior  part  of  the  corpus  callosum  forms  in  front  a  bend,  the 
genu,  and  this  extends  back  along  the  base  of  the  brain  up  to  the  lamina 
cinerea  as  the  rostrum.  Here  it  sends  oiF  the  peduncles  of  the  corpus 
callosum.  Behind  it  forms  a  thick  border,  the  splenium  or  pad.  The 
under  surface  of  the  corpus  callosum  is  connected  behind  with  the  fornix 
and  for  the  rest  of  its  extent  with  the  septum  lucidum.  It  forms  the 
roof  of  the  lateral  ventricles. 

Describe  the  lateral  ventricles. 

These  serous  cavities  have  a  thin  lining  membrane  covered  by  a  layer 
of  epithelium  cells  {ependyma)  which  secretes  a  serous  fluid.  They  are 
contained  one  in  each  hemisphere,  separated  by  the  septum  lucidum,  and 
each  is  divided  into  a  body  and  three  cornua,  an  anterior,  posterior,  and 
middle.     The  foramen  of  Monro  connects  them  with  the  third  ventricle. 

The  central  cavity  or  body  is  roofed  by  the  corpus  callosum,  and  in 
the  floor,  from  without  inward,  are  found  the  caudate  nucleus  of  the 
corpus  striatum,  taenia  semicircularis,  part  of  the  optic  thalamus,  cho- 
roid plexus,  and  part  of  the  fornix. 

The  anterior  cornu  projects  into  the  anterior  lobe  and  runs  outward 
round  the  nucleus  caudatus.  Above  and  in  front  of  it  is  the  corpus 
callosum. 

The  posterior  cornu,  or  digital  cavity,  runs  back  into  the  posterior 
lobe,  its  direction  being  backward,  outward,  and  lastly  inward.  Its  floor 
presents  the  eminence  of  the  hippocampus  minor  or  calcar  avis.  At  the 
junction  of  the  posterior  and  middle  cornua  is  the  eminentia  collateralis 
or  pes  accessorius. 

The  middle  or  descending  cornu  curves  round  the  back  of  the  optic 
thalamus,  descending  at  first  backward  and  outward.  It  then  runs 
downward,  forward,  and  lastly  inward.  In  its  floor  are  the  hippocam- 
pus major  and  pes  hippocampi,  corpus  fimbriatum,  and  choroid  plexus ; 


260  THE   BRAIN   OR   ENCEPHALON. 

the  fascia  dentata  lies  within  the  hippocampal  or  dentate  fissure,  and  the 
transverse  fissure  runs  along  the  inner  side  of  the  cornu. 

Describe  these  parts  in  detail. 

The  corpus  striatum  is  a  mass  of  gray  matter,  and  consists  of  an 
extraventricular  portion  imbedded  in  the  hemisphere  and  called  the  len- 
ticular nucleus,  and  an  intraventricular  part  in  the  body  and  anterior 
cornu,  the  nucleus  caudatus. 

The  caudate  nucleus  is  pyriform,  projecting  into  the  body  and  anterior 
cornu  by  its  broad  end,  and  by  its  smaller  end  into  the  roof  of  the  mid- 
dle cornu  nearly  to  its  tip. 

The  lenticular  nucleus  is  divided  into  three  zones,  visible  on  transverse 
vertical  section.  It  is  separated  from  the  caudate  nucleus  by  the  internal 
capsule^  and  the  external  capsule  separates  it  from  the  claustrum.  This 
nucleus  and  the  caudate  are  joined  together  in  front,  and,  behind,  the 
lenticular  is  continuous  with  the  gray  matter  of  the  anterior  perforated 
space. 

The  claustrum  is  a  gray  lamina  marked  externally  by  ridges  and  fur- 
rows corresponding  to  the  gyri  and  sulci  of  the  island  of  Reil. 

The  nucleus  amygdalce  is  a  small,  yellowish-gray  mass  projecting  into 
the  apex  of  the  middle  cornu,  and  continuous  with  the  cortical  part  of 
the  apex  of  the  temporo-sphenoidal  lobe. 

The  taenia  semicircularis  lies  in  a  groove  between  the  caudate  nu- 
cleus and  the  optic  thalamus.  In  front  it  joins  the  anterior  pillar  of  the 
fornix ;  behind  it  enters  the  nucleus  amygdalae.  Beneath  it  is  the  vena 
corporis  striati. 

The  choroid  plexus  is  a  very  vascular  fringe  covered  with  epithe- 
lium continuous  with  that  of  the  ependyma,  and  forms  the  border  of 
the  velum  interpositum.  It  extends  from  the  foramen  of  Monro,  where 
it  is  continuous  with  the  other,  across  the  floor  of  the  body  of  the  ven- 
tricle and  into  the  middle  cornu. 

The  corpus  flmbriatum  is  the  narrow  band  of  white  matter  on  the 
hippocampus  major  into  which  is  prolonged  the  posterior  pillar  of  the 
fornix. 

The  hippocampus  major  is  a  curved  white  prominence  in  the  floor 
of  the  middle  horn.  Its  lower  part  presents  the  appearance  of  a  paw 
from  its  grooves  and  eminences,  hence  called  the  pes  hipj^ocampi.  The 
hippocampus  major  is  caused  by  the  dentate  fissure,  and  the  gray  matter 
contained  in  this  fissure  (dentate  convolution)  projects  as  a  free  margin— 
the  fascia  dentata. 

The  eminentia  collateralis  (pes  accessorius)  is  formed  by  the  col- 
lateral fissure  (occipito-temporal). 

The  great  transverse  fissure  of  Bichat,  separating  the  cerebrum 
and  cerebellum,  lies  between  the  fornix  and  the  splenium  of  the  corpus 
callosum  above  and  the  corpora  quadrigemiiia  below ;  laterally,  it  lies 
between  the  back  part  of  the  optic  thalamus  below  and  the  corpus  fim- 
briatum  and  fascia  dentata  above. 


THE   OPTIC  THALAMI.  261 

The  septum  lucidum  separates  the  lateral  ventricles;  It  is  com- 
posed of  two  laj^ers,  a  small  space  containing  fluid  being  left  between 
them  called  the  fifth  ventricle.  It  is  attached  above  to  the  corpus  cal- 
losum,  below  to  the  anterior  part  of  the  fornix  and  the  reflected  portion 
of  the  corpus  callosum. 

The  fornix  is  an  arched  longitudinal  commissure  of  white  matter  be- 
low the  corpus  callosum,  its  lateral  margins  forming  part  of  the  floor  of 
the  body  of  the  lateral  ventricles.  In  front  its  two  lateral  halves  are 
divergent,  and  form  the  ariterior  pillars ;  behind  they  diverge  into  the 
two  posterior  pillars ;  the  central  part  is  the  body.  The  body  is  trian- 
gular, attached  above  to  the  corpus  callosum  and  septum  lucidum  ;  be- 
low^ the  velum  interpositum  separates  it  from  the  third  ventricle  and 
optic  thalami.     On  each  side  project  the  choroid  plexuses. 

The  anterior  pillars  descend  through  the  gray  matter  on  the  sides  of 
the  third  ventricle  and  form  the  anterior  boundaries  of  the  foramen  of 
Monro.  ^  Then  they  emerge  at  the  base  of  the  brain  to  form  the  corpora 
albicantia,  from  which  each  pillar  turns  upward  and  ends  in  the  cor- 
responding optic  thalamus.  In  their  course  each  communicates  with  the 
peduncle  of  the  pineal  gland  and  the  taenia  semicircularis. 

The  posterior  pillars  are  connected  with  the  corpus  callosum,  then 
enter  the  descending  cornu^,  and  are  partly  prolonged  into  the  upper 
surface  of  hippocampus  major  and  partly  into  the  corpus  fimbriatum. 

The  foramen  of  Monro  is  a  foramen  connecting  each  lateral  ven- 
tricle with  the  anterior  part  of  the  third.  In  front  it  is  bounded  by  the 
anterior  pillar  of  the  fornix ;  behind,  by  the  anterior  part  of  the  optic 
thalamus ;  above,  by  the  anterior  extremity  of  the  body  of  the  fornix. 

What  is  the  velum  interpositum? 

The  velum  interpositum  is  a  process  of  the  pia  mater  which  oc- 
cupies the  great  transverse  fissure,  and  hence  separates  the  fornix  from 
the  third  ventricle.  In  front  it  sends  a  process  through  the  foramen  of 
Monro  to  each  lateral  ventricle.  From  its  under  surface  it  supplies  the 
two  vascular  processes  which  form  the  choroid  plexuses  of  the  third 
ventricle,  and  on  each  side  the  choroid  plexuses  of  the  lateral  ventricles 
are  found. 

What  are  the  optic  thalami  ? 

The  optic  thalami  are  two  masses  composed  externally  of  white, 
internally  of  gray  matter,  and  rest  upon  the  tegmentum  of  the  crura. 
The  fibres  of  the  crusta,  forming  the  internal  capsule^  separate  the  outer 
surface  of  each  from  the  lenticular  nucleus  of  the  corpus  striatum.  The 
inner  surface  of  each  forms  the  lateral  boundaries  of  the  third  ventricle ; 
its  upper  surface  is  grooved,  and  presents  in  front  the  projection  of  the 
anterior  tubercle.  Fart  of  the  under  surface  forms  part  of  the  roof  of 
the  descending  cornu  ;  the  anterior  extremity  is  the  hinder  boundary  of 
the  foramen  of  Monro. 


262  THE   BRAIN   OR   ENCEPHALON. 

Describe  the  third  ventricle. 

This  is  the  expanded  interval  into  which  the  Sylvian  aqueduct  opens, 
and  which  lies  between  the  optic  thalami.  The  velum  intevpositum^  with 
the  choroid  plexuses,  connected  on  each  side  with  the  peduncles  of  the 

fnneal  gland,  forms  its  roof,  together  with  the  posterior  commissure, 
ts  floor  presents  the  lamina  cinerea,  tuber  cinereum,  infundibulum,  cor- 
pora albicantia,  posterior  perforated  space,  and  tegmentum  of  crura. 
In  front  it  is  bounded  by  the  anterior  commissure  and  the  lamina  cine- 
rea.    Behind  is  the  opening  of  the  aqueduct  of  Sylvius. 

In  its  cavity  are  three  commissures :  the  anterior,  in  front  of  the  ante- 
rior pillars  of  the  fornix,  piercing  on  each  side  the  corpus  striatum ;  the 
middle  or  soft,  of  gray  matter,  connecting^  the  thalami ;  and  the  poste- 
rior, also  connecting  the  optic  thalami  behind,  and  lying  in  front  of  and 
beneath  the  pineal  gland. 

In  front  are  the  two  openings,  one  on  each  side,  of  the  foramen  of 
Monro. 

Describe  the  parts  in  relation  with  the  Sylvian  aqueduct. 

The  pineal  gland  (epiphysis  cerebri)  is  a  small  reddish  body  placed 
between  and  upon  the  upper  pair  of  corpora  quadrigemina.  It  has  two 
peduncles,  which  run  along  the  junction  of  the  inner  and  upper  surfaces 
of  the  optic  thalami  to  join  the  anterior  pillars  of  the  fornix.  Just  be- 
fore entering  the  pineal  gland  they  are  joined  together,  the  connecting 
band  joining,  in  front,  the  posterior  commissure.  This  gland  is  a  collec- 
tion of  follicles  containing  a  clear,  viscid  matter  and  the  brain  sand 
(acervulus  cerebri),  a  kind  of  phosphatic  calculi. 

The  corpora  quadrigemina  are  rounded  masses  of  gray  matter 
thinly  covered  with  white,  arranged  as  an  upper  and  a  lower  pair.  They 
lie  above  the  Sylvian  aqueduct  and  behind  the  posterior  commissure,  and 
upon  the  terminations  of  the  superior  peduncles  of  the  cerebellum  of 
each  side.  The  anterior  or  upper  pair  are  the  larger.  On  each  side 
they  are  connected  with  the  thalami  and  optic  tracts  by  white  bands, 
the  brachia,  anterior  and  posterior. 

The  geniculate  bodies  lie  against  the  under  and  back  part  of  each 
thalamus,  external  to  the  corpora  quadrigemina.  They  are  named  ex- 
ternal and  internal,  and  are  separated  by  one  of  the  roots  of  the  optic 
tract. 

Describe  the  cerebellum. 

The  cerebellum  is  that  part  of  the  cerebro-spinal  axis  which  is  con- 
tained in  the  inferior  occipital  fossae.  Its  weight  is  about  one-eighth 
that  of  the  cerebrum,  being  proportionately  large  in  the  infant.  It  con- 
sists of  gray  matter  externally,  white  internally. 

Describe  its  upper  surface. 

The  upper  surface  presents  a  median  elevation,  the  superior  vermi- 
form process,  which  connects  together  the  upper  surfaces  of  the  two 


THE   CEREBELLUM.  263 

hemispheres  of  the  organ.  In  front  and  behind  the  hemispheres  are 
separated  by  two  notches,  the  incisura  cerebelli  anterior  and  posterior 
respectively. 

Describe  the  superior  vermiform  process. 

It  is  divided  into  four  lobes,  the  Imgula,  the  lohuliis  centralis^  mon- 
ticulus  cerebelli^  and  commissura  simplex^  or  folium  cacuminis.  The  first 
is  on  the  valve  of  Vieussens,  the  second  is  in  the  anterior,  the  last  in 
the  posterior  incisura,  and  the  third  is  the  most  prominent  part  of  the 
process. 

Describe  the  under  surface  of  the  cerebellum. 

The  under  surfaces  of  the  hemispheres  are  separated  by  the  vallecula, 
in  which  is  found  the  inferior  vermiform  process,  on  which  from  behind 
forward  are  found  the  following :  commissura  hrevis  or  tuber  valvulse, 
pyramid,  uvula,  lying  between  the  amygdalae  and  joined  with  them  by 
the  furrowed  hand  and  nodule,  with  the  inferior  medullary  velum  on 
each  side. 

Mention  the  lobes  of  the  cerebellar  hemispheres. 

Each  hemisphere  presents  numerous  deep  and  curved  fissures  very 
close  together.  The  largest,  the  great  horizontal  fissure,  runs  from  the 
point  of  emergence  of  the  peduncles  on  each  side,  to  end  at  the  same 
point  as  its  opposite  fellow  in  the  incisura  posterior.  Secondary  fissures 
proceed  from  it  in  various  directions.  The  great  fissure  divides  each 
hemisphere  into  an  upper  and  a  lower  part,  and  the  secondary  fissures 
divide  them  into  lobes.     These  lobes  are  the  following : 

Upper  surface,  anterior  or  square  lobe ;  posterior  or  semilunar  lobe. 

Under  surface,  from  before  backward,  the  flocculus  or  pneumogastric 
lobule ;  tonsil  or  amygdala ;  digastric  or  biventral  lobe  ;  slender  lobe 
(gracilis) ;   and  the  inferior  posterior  or  postero-inferior  lobe. 

Name  and  describe  the  peduncles  of  the  cerebellum. 

They  connect  the  cerebellum  with  the  other  parts  of  the  encepha- 
lon.  They  are  the  superior,  middle,  and  inferior  peduncles  of  the  cere- 
bellum. 

The  first  run  to  and  beneath  the  corpora  quadrigemina,  and  form  part 
of  the  roof  of  the  fourth  ventricle,  the  valve  of  Vieussens  lying  between 
the  two ;  the  second  are  the  prolongation  of  the  transverse  fibres  of  the 
pons ;  and  the  third  are  simply  the  upper  part  of  the  restiform  bodies. 
They  are  all  of  white  matter. 

What  is  the  arbor  vitse  ? 

It  is  the  name  given  to  the  arrangement  of  the  white  matter  of  the 
cerebellum  as  seen  on  a  median  section.   (See  Fig.  14.) 

Describe  the  fourth  ventricle. 

The  fourth  ventricle  is  placed  between  the  medulla  and  pons  in  front 
and  the  cerebellum  behind.     It  is  diamond-shaped,  the  lower  triangle 


264 


THE   BRAIN   OR   ENCEPHALON. 
Fig.  14. 


Right  half  of  the  Encephalic  Peduncle  and  Cerebellum  as  seen  from  the  inside  of  a 
median  section  (Allen  Thompson,  after  Reichert):  P?',  pons  Varolii  divided  in  the 
middle;  m,  medulla  oblongata;  c,  central  canal,  divided  longitudinally,  with  gray- 
substance  surrounding  it;  V^,  middle  of  the  fourth  ventricle.  In  the  cerebel- 
lum, nv,  stem  of  white  substance  in  the  centre  of  the  middle  lobe  of  the  cerebellum, 
ramifying  into  the  arbor  vitse ;  sv,  superior  vermiform  process  or  upper  portion  of 
the  middle  lobe;  5C,  single  folium  (folium  cacuminis),  which  passes  across  the  pos- 
tero-superior  lobes;  c',  the  tuber  valvulse;  p,  pyramid;  w,  uvula;  n,  nodule;  1  to  2, 
laminse  of  the  monticulus  cerebelli ;  between  V^  and  1  are  seen  the  lingula  and  cen- 
tral lobe  in  section;  3,  postero-inferior  lobe;  4,  lobulus  gracilis;  5,  biventral  lobe; 
6,  amygdaloid  lobe.  II,  right  optic  nerve ;  behind  it  the  optic  commissure  divided ; 
III,  right  third  nerve ;  VI,  sixth  nerve ;  V^  third  ventricle ;  Th,  back  part  of  the 
thalamus  opticus;  H,  section  of  the  pituitary  body;  p,  pineal  gland;  below  its  stalk 
is  the  posterior  commissure;  ca,  anterior  commissure  divided,  and  behind  it  the 
divided  anterior  pillar  of  the  fornix ;  /c,  lamina  cinerea;  i,  infundibulum  (cavity); 
tc,  tuber  cinereum  ;  behind  it  the  corpus  albicans  ;  /,  mark  of  the  anterior  pillar  of 
the  fornix  descending  in  the  wall  of  the  third  ventricle ;  cm,  commissura  mollis ; 
sp,  stria  piuealis  or  peduncle  of  pineal  gland ;  Q,  corpora  quadrigemina ;  as,  aqueduct 
of  Sylvius  near  the  fourth  ventricle ;  cr,  crus  cerebri. 

being  bounded  laterally  by  the  clavce  of  the  funiculi  graci'les,  the  cuneate 
fasciculi^  and  the  restiform  bodies ;  the  upper  by  the  superior  peduncles 
of  the  cerebellum.  Below  it  is  continuous  with  the  central  canal  of  the 
cord ;  above,  with  the  Sylvian  aqueduct.     Laterally  it  projects,  as  the 


THE    FOURTH    VENTRICLE.  265 

lateral  recesses,  to  the  point  of  contact  of  the  medulla  and  cerebellum, 
.this  being  its  widest  part.  The  lower  pointed  part  of  the  ventricle  is 
called  the  calamus  scriptorms. 

The  roof  of  the  lower  triangle  is  formed  by  a  layer  of  epithelium  cover- 
ing the  under  surface  of  the  pia  mater ;  that  of  the  upper  triangle  is 
formed  by  the  valve  of  Vieussens,  together  with  the  superior  peduncles^ 
in  the  upper  part.  The  valve  of  Vieussens  is  streaked  transversely  by 
several  laminae  of  gray  matter  separated  by  grooves,  forming  the  lingida, 
which  is  a  part  of  the  superior  vermiform  process  of  the  cerebellum. 

Describe  the  valve  of  Vieussens. 

The  valve  of  Vieussens,  or  the  superior  medullary  velum,  is  a  white 
lamina  between  the  superior  peduncles  of  the  cerebellum.  Its  upper 
part  presents  a  ridge,  the  frenulum,  on  each  side  of  which  is  the  fourth 
nerve,  joined  by  a  transverse  band  with  the  opposite  nerve. 

Describe  the  floor  of  the  fourth  ventricle  and  accessory  struc- 
tures. 

The  epithelium  forming  the  roof  of  the  lower  triangle  is  continuous  with 
that  covering  the  floor,  arid  is  thickened  by  some  white  matter,  which  runs 
for  some  distance  along  the  edge  of  the  lateral  boundary,  from  the  lateral 
recess  above,  nearly  to  the  calamus  scriptorius  below.  This  constitutes 
the  taenia  or  ligula.  The  epithelium  is  also  thickened  over  the  point  of 
the  calamus,  and  is  here  called  the  obex.  The  two  choroid  plexuses  of 
the  fourth  ventricle  depend  from  the  roof,  covered  by  epithelium.  They 
send  processes  into  the  lateral  recesses,  around  which  part  of  the  ligula 
is  reflected,  forming  the  cornucopia.  The  floor,  medullary  portion,  pre- 
sents several  white  lines,  the  strice  acousticce,  which  run  outward  from 
the  median  line  across  the  restiform  body  to  the  auditory  nerve.  The 
floor  presents  also  a  mesial  groove,  on  each  side  of  which,  below  the  striae 
acousticae,  toward  which  the  apex  is  turned,  is  a  small  triangular  depres- 
sion, the  inferior  fovea.  Its  base  sends  off  a  groove  from  each  angle, 
the  inner  of  which  runs  toward  the  point  of  the  calamus  scriptorius, 
marking  off  between  it  and  the  median  groove,  the  prominent  lower  por- 
tion of  i\iQ  fasciculus  teres,  triangular  in  shape  with  its  base  toward  the 
striae.  The  outer  runs  outward  to  the  lateral  boundary  of  the  ventricle, 
and  bounds  a  third  triangular  space  with  its  base  upward,  ending  near 
the  striae  in  the  acoustic  tubercle. 

Between  the  two  grooves  just  mentioned  is  a  dark,  somewhat  trian- 
gular space,  the  ala  cinerea,  its  narrower  part  at  the  inferior  fovea,  its 
broader  side  downward,  forming  the  eminentia  cinerea.  Yentrally,  this 
space  practically  includes  the  nuclei  of  the  ninth,  tenth,  and  eleventh 
nerves. 

The  upper  part  of  the  floor  of  the  fourth  ventricle  presents,  just  above 
the  inferior  fovea  on  each  side,  a  somewhat  similar  depression,  the 
superior  fovea.  Between  it  and  the  mesial  groove  is  the  upper  part  of 
the  fasciculus  teres,  and  running  from  it  toward  the  iter  above  is  a  groove, 


266  CRANIAL   NERVES. 

the  locus  ccerulem.     The  color  of  the  latter  is  due  to  a  line  of  pigmented 
nerve-cells  forming  the  substantia  fer'ruginea. 

In  the  floor  of  the  fourth  ventricle  are  also  found  the  nuclei  from  which 
arise  the  fifth  nerve,  the  seventh,  eighth,  and  sixth.  That  for  the  fifth, 
its  motor  portion,  lies  below  the  lateral  angle,  and  its  sensory  portion, 
more  extensive,  lies  external  to  the  latter ;  that  for  the  seventh  behind 
the  superior  olivary  nucleus  of  the  pons ;  that  for  the  sixth,  in  a  column 
of  multipolar  cells  in  the  fasciculus  teres,  above  the  striae  acousticae ; 
and  for  the  eighth  the  nuclei  lie  under  the  acoustic  tubercle  and  striae. 
The  nuclei  of  the  third  and  fourth  nerves  are  in  the  floor  of  the  aqueduct 
of  Sylvius,  and  that  of  the  twelfth  is  in  the  fasciculus  teres  below  the 
striae  acousticae. 

CRANIAL  NERVES. 

How  many  cranial  nerves  are  there?    What  are  their  names? 

The  cranial  nerves  consist  of  twelve  pairs,  as  follows : 

1st  pair.  Olfactory ;  7th  pair,  Facial,  portio  dura ; 

2d  pair,  Optic ;  8th  pair,  Auditory,  portio  moUis ; 

3d  pair.  Motor  oculi ;  9th  pair,  Glosso-pharyngeal ; 

4th  pair.  Pathetic;  10th  pair,  Pneumogastric ; 

5th  pair.  Trifacial;  11th  pair.  Spinal  accessory; 

6th  pair,  Abducens;  12th  pair.  Hypoglossal. 

What  are  the  origins  of  the  cranial  nerves  ? 

These  nerves  have  each  a  superficial  and  a  deep  origin.  The  former 
corresponds  to  its  point  of  attachment  at  the  surface  of  the  brain ;  the 
latter  to  certain  nuclei  or  collections  of  nerve-cells  in  the  floor  of  the 
fourth  ventricle  and  Sylvian  aqueduct. 

Describe  the  olfactory  nerves. 

The  olfactory  nerves,  twenty  on  each  side,  descend  from  the  under 
surface  of  the  olfactory  bulb  through  the  cribriform  plate  to  the  nose. 
Internally  they  groove  the  vertical  plate  of  the  ethmoid ;  externally,  the 
inner  surface  of  the  lateral  mass.     They  are  all  non-medullated  nerves. 

Describe  the  optic  nerves. 

The  optic  nerves  of  the  two  sides  meet  and  partially  decussate  at  the 
commissure  or  chiasma,  back  of  which  they  enter  the  brain  as  the  optic 
tracts.  Each  tract  arises  from  the  optic  thalamus,  corpora  geniculata, 
and  the  superior  corpus  quadrigeminum  as  a  flat  band.  This  flattened 
band  then  crosses  the  cms  cerebri,  and,  becoming  rounded  in  form,  is 
adherent  to  the  tuber  cinereum  and  lamina  cinerea. 

The  commissure  lies  on  the  olivary  eminence  of  the  sphenoid  bone,  and 
in  it  most  of  the  fibres  decussate.  The  outer,  however,  are  prolonged 
into  the  nerve  of  the  same  side.  From  the  commissure  each  optic  nerve 
runs  through  the  foramen  opticum,  ensheathed  by  the  dura  mater  and 


PLATE  XXI. 

Fig.  1.  — To  face  page  267. 


Motor  root. 
Sensory  root. 


Eecurrent  filament 
to  dura  mater. 


Nerves  of  the  Orbit,  seen  from  above. 


PLATE  XXII. 

Fig.  1 . — To  face  page  i 


Internal  carotid  artery 
and  carotid  plexus. 


Nerves  of  the  Orbit  and  Ophthalmic  Ganglion  (side  view). 
Fig.  2.  —  To  face  page  272. 


External  'petrosal. 
Small  superficial  petrosal.-^ 
Large  superficial  petrosal.^^r 

Intumescentia  ganglioformis.      ^ 


Seventh  pair  {^^''^^1:^ 
The  Course  and  Connections  of  the  Facial  Nerve  in  the  Temporal  Bone, 


THE   FIFTH    NERVE.  267 

arachnoid,  and  pierces  the  eyeball  just  inside  its  centre,  and,  after  run- 
ning through  the  sclerotic  and  choroid,  expands  to  form  the  retina. 

Describe  the  motor  oculi. 
The  motor  oculi  arises  superficially  from  the  crus  anterior  to  the 

§ons,  its  deep  origin  being  a  gray  nucleus  in  the  floor  of  the  aqueduct  of 
ylvius.  It  runs  to  the  outer  side  of  the  posterior  clinoid  process,  enters 
the  cavernous  sinus,  runs  above  the  other  nerves  in  its  outer  wall,  and 
divides  into  two  branches^  which  enter  the  orbit  between  the  two  heads 
of  the  external  rectus.  It  is  joined  in  the  sinus  by  sympathetic  fila- 
ments. The  superior  branch  crosses  the  optic  nerve  to  supply  the  superior 
rectus  and  levator  palpebrae.  The  inferior  divides  into  three  parts — one 
for  the  inferior  oblique,  one  to  the  inner  and  one  to  the  lower  rectus. 
The  first  supplies  the  motor  root  of  the  lenticular  ganglion. 

Describe  the  pathetic. 

The  pathetic  nerve  has  an  apparent  origin  from  the  upper  side  of 
the  valve  of  Vieussens,  and  a  deep  from  the  floor  of  the  aqueduct  of 
Sylvius.  The  two  nerves  communicate  by  a  transverse  band  on  the 
valve  of  Vieussens.  The  nerve  pierces  the  dura  after  crossing  over  the 
crus,  enters  the  cavernous  sinus,  in  whose  outer  wall  it  lies  between  the 
ophthalmic  and  third  nerves,  then  crosses  the  latter  to  enter  the  orbit 
through  the  sphenoidal  fissure  above  the  external  rectus,  and  enters  the 
superior  oblique  after  crossing  over  the  levator  palpebrae.  It  receives 
sympathetic  filaments  in  the  sinus,  and  sends  a  recurrent  branch  into  the 
tentorium. 

Describe  the  fifth  nerve. 

The  fifth  or  trifacial  is  the  largest  of  all  the  cranial  nerves,  and  arises 
by  two  roots,  a  motor  and  a  sensory.  The  former  is  small,  and  the  latter 
has  the  Gasserian  ganglion  upon  it.  Both  arise  from  the  side  of  the 
pons  superficially,  the  smaller  root  above  the  larger,  some  transverse 
fibres  of  the  pons  separating  the  two.  This  nerve  confers  both  motion 
and  sensation.  At  the  apex  of  the  petrous  portion  of  the  temporal  the 
large  root  forms  the  Gasserian  ganglion ;  the  smaller  does  not  join  in  the 
ganglion,  but  runs  below  it  to  join,  just  below  the  foramen  ovale,  the 
lowest  trunk  proceeding  from  the  ganglion. 

Describe  the  Gasserian  ganglion. 

The  Gasserian  ganglion  lies  in  a  hollow  near  the  apex  of  the  petrous 
portion  of  the  temporal,  the  large  superficial  petrosal  nerve,  and  the 
motor  root  lying  below  it.  It  receives  branches  from  the  carotid  plexus. 
Small  twigs  pass  to  the  dura  mater.  This  ganglion  sends  off"  three  large 
branches — viz.  the  ophthalmic,  superior  maxillary,  and  inferior  maxillary. 

The  first  two  confer  sensation,  the  third  motion  and  sensation. 

Describe  the  ophthalmic  nerve. 
The  ophthalmic  or  first  division  of  the  fifth  nerve  is  sensory,  and  the 


268  CRANIAL   NERVES. 

smallest  branch  of  the  ganglion.  It  is  flattened,  about  1  inch  long,  and 
runs  in  the  outer  wall  of  the  cavernous  sinus,  being  the  lowest  of  the 
nerves.  It  receiYes  filaments  from  the  cavernous  plexvs,  and  gives  off" 
filaments  to  the  third  and  sixth,  and  sometimes  to  the  fourth  nerve,  and 
a  recurrent  branch  running  in  the  tentorium  with  the  fourth.  Finally  it 
divides  into  the  frontal,  lachrymal,  and  nasal  nerves,  which  pass  through 
the  sphenoidal  fissure  into  the  orbit. 

The  lachrymal,  the  smallest,  runs  with  the  lachrymal  artery  above 
the  external  rectus  muscle  to  the  gland,  which  it  supplies,  as  well  as  the 
conjunctiva,  communicating  with  the  superior  maxillary  nerve.  It  then 
pierces  the  palpebral  ligament  to  end  in  the  upper  lid,  joining  branches 
of  the  facial. 

The  frontal,  the  largest  branch,  enters  the  orbit  through  the  widest 
part  of  the  sphenoidal  fissure,  just  below  the  periosteum,  and  divides 
about  the  middle  of  the  orbit  into  the  supratrochlear  and  supraorbital 
nerves.  The  former  runs  in  over  the  pulley. of  the  superior  oblique,  and 
leaves  the  orbit  between  it  and  the  supraorbital  foramen.  It  then  ascends 
beneath  the  muscles  and  ends  in  the  skin  of  the  forehead.  It  communi- 
cates in  the  orbit  with  the  infratrochlear  nerve.  The  frontal  nerve  con- 
tinues as  the  supraorbital,  which  passes  through  the  supraorbital  foramen, 
supplies  the  upper  lid,  and  divides  into  an  inner  and  an  outer  branch. 
These  ascend  on  the  forehead  and  supply  the  pericranium  and  skin,  the 
outer  reaching  nearly  to  the  lambdoid  suture. 

The  nasal  enters  the  orbit  between  the  two  divisions  of  the  third  nerve, 
and  between  the  heads  of  the  external  rectus,  and  then  crosses  over  the 
optic  nerve  and  runs  to  the  anterior  ethmoidal  foramen.  In  the  orbit  it 
gives  oiFa  branch  to  the  ophthalmic  ganglion,  several  long  ciliafinj  to  the 
eyeball,  and  an  infratrochlear  branch.  It  then  re-enters  the  cranial 
cavity  through  the  anterior  ethmoidal  canal.  In  the  cranium  it  runs 
in  a  groove  on  the  cribriform  plate,  and  through  a  slit  on  the  side  of 
the  crista  galli  into  the  nose,  where  it  gives  off  an  external  and  an  inter- 
nal branch.  The  latter  supplies  the  mucous  membrane  of  the  septum, 
and  the  external  the  outer  wall  of  the  nasal  fossa.  The  nerve  then 
runs  in  the  groove  on  the  nasal  bone  to  end  as  the  anterior  branch  in 
the  integument  of  the  tip  of  the  nose,  joining  facial  branches. 

Describe  the  ophthalmic  ganglion. 

It  is  found  at  the  back  of  the  orbit,  between  the  optic  nerve  and  the 
external  rectus.  It  has  three  roots — viz.  the  long  or  sensory,  from  the 
nasal  branch  of  the  ophthalmic ;  a  short  or  motor,  from  the  branch  of 
the  third  to  the  inferior  oblique ;  and  the  sympathetic  root,  from  the 
cavernous  plexus. 

Branches :  six  or  eight  short  ciliary,  which  run  with  the  ciliaiy  arteries 
above  and  below  the  optic  nerve,  and  are  joined  by  the  long  ciliary  from 
the  nasal.     They  pierce  the  sclerotic  to  supply  the  ciliary  muscle  and 


269 

Describe  the  second  division  of  the  fifth    (superior  maxillary) 
nerve. 

It  is  sensorj'^,  and  enters  the  foramen  rotundum,  crosses  the  spheno- 
maxillary fossa,  and,  as  the  infraorbital,  traverses  the  canal,  emerges 
from  the  foramen  to  end  on  the  face  in  palpebral^  nasal,  and  labial 
branches :  the  first,  to  lower  lid ;  the  second,  to  side  of  nose ;  and  the 
third  set,  to  upper  lip.  These  branches  join  with  the  facial  to  form  the 
infraorbital  plexus.  The  superior  maxillary  nerve  also  gives  ofi"  two 
branches  to  MeckeVs  ganglion,  an  orbital  and  alveolar  branches,  and  a 
recurrent  branch  to  the  dura  mater. 

The  orbital  or  temporo-malar  branch  enters  the  orbit  by  the  spheno- 
maxillary fissure,  and  divides  into  two  branches,  which  pierce  the  malar 
bone.  The  malar  branch  supplies  the  skin  of  the  cheek,  and  joins  the 
facial.  The  temporal  branch,  after  piercing  the  malar  bone,  enters  the 
temporal  fossa,  and  ends  in  the  skin  over  the  fore  part  of  the  temporal 
region,  joining  the  facial  and  auriculo-temporal  nerves. 

The  alveolar  or  superior  dental  nerves  are  three.  The  posterior 
divides  into  two,  which  run  on  the  zygomatic  surface  of  the  sup.  maxilla, 
supplying  the  gum  and  the  mucous  membrane  of  the  cheek,  and  enter 
the  posterior  dental  canals  to  the  molar  teeth.  The  middle  runs  to  the 
bicuspids  along  a  canal  in  the  antrum.  The  anterior  descends  in  its 
canal,  and  (gives  a  nasal  branch  to  the  pituitary  membrane,  and  dental 
branches  to  the  canine  and  incisor  teeth. 

Describe  Meckel's  ganglion. 

It  is  also  called  the  spheno-palatine,  and  lies  in  the  spheno-maxillary 
fossa,  close  to  the  spheno-palatine  foramen  and  below  the  superior  max- 
illary nerve.  Its  motor  root  comes  from  the  facial  (see  Vidian  nerve), 
its  sensory  root  from  the  two  ganglionic  branches  of  the  superior  max- 
illary nerve,  and  the  sympathetic  root  from  the  carotid  plexus.  Its 
branches  are  as  follows: 

Ascending :  Several  through  the  spheno-maxillary  fissure  to  the 
orbit.     They  may  supply  the  periosteum. 

Descending  :  The  small  or  posterior  runs  with  a  small  artery  in  the 
lesser  palatine  canal.     It  supplies  the  levator  palati  and  azygos  uvulae. 

The  large  or  anterior  runs  in  the  posterior  palatine  canal,  thence  in 
branches  to  the  incisor  teeth  along  grooves  in  the  hard  palate,  and  one 
joins  the  naso-palatine  nerve.  It  gives  off*  inferior  nasal  branches, 
through  canals  in  the  palate  bone,  to  supply  i\\e  spongy  bones. 

The  external,  to  the  outer  part  of  the  soft  palate,  through  the  exter- 
nal palatine  canal. 

The  internal  branches  include  the  naso-j)alatine  and  the  upper  nasal 
nerves.  The  latter  run  through  the  spheno-palatine  foramen  to  the  spongy 
bones  and  septum.  The  naso-palatine  nerve  proceeds  with  the  above, 
and  then  descends  on  the  septum  nasi,  beneath  the  pituitary  membrane, 
and  through  the  mesial  divisions  of  the  anterior  palatine  canal,  called 


270  CRANIAL   NERVES. 

the  foramina  of  Scarpa,  the  left  anterior  to  the  right.  They  supply  the 
mucous  membrane  behind  the  incisor  teeth. 

The  posterior  branches  are  the  Vidian  and  pharyngeal  nerves.  The 
Vidian  passes  back  through  the  Vidian  canal,  and  divides  in  the  foramen 
lacerum  medium  into  the  great  superficial  petrosal  and  the  great  deep 
petrosal.  The  former  passes  through  the  foramen  lacerum  medium, 
runs  in  a  groove  on  the  anterior  surface  of  the  petrous  portion  of  the 
temporal,  enters  the  hiatus  Fallopii,  communicates  with  Jacobson's  nerve, 
enters  the  aqueductus  Fallopii,  and  joins  the  geniculate  ganglion  of  the 
seventh  nerve.  The  deep  runs  backward  and  joins  the  sympathetic  in 
the  carotid  canal. 

The  phary?igeal  nerve  passes  through  the  pterygo-palatine  canal  to 
the  mucous  membrane  of  the  pharynx. 

Describe  the  inferior  maxillary  nerve. 

It  is  the  largest  branch,  and  arises  by  two  roots — a  large  sensory  root 
from  the  Gasserian  ganglion  and  the  motor  root  of  the  fifth.  This 
nerve  divides  into  two  trunks,  anterior  and  posterior.  The  anterior 
gives  off  the  masseteric,  the  buccal  the  deep  temporal  and  the  two 
pterygoid. 

The  masseteric  runs  above  the  external  pterygoid,  crosses  the  sig- 
moid notch  to  masseter,  supplying  also  filaments  to  the  jaw. 

The  deep  temporal  are  three,  the  posterior,  middle,  and  anterior. 

The  buccal  is  a  sensory  nerve,  and  runs  along  the  inner  surface  of  the 
coronoid  process  to  divide,  on  the  buccinator,  into  branches  to  the 
muscles  and  skin  joining  the  facial,  and  extending  as  far  as  the  angle 
of  the  mouth. 

The  pterygoid,  internal  and  external,  supply  those  muscles  respec- 
tively. 

The  posterior  trunk  of  the  inferior  maxillary  is  mostly  sensory.  It 
divides  into  the  auriculo-temporal,  gustatory,  and  inferior  dental. 

The  auriculo-temporal  runs  beneath  the  external  pterygoid,  the 
middle  meningeal  artery  passing  up  between  its  two  roots  of  origin  to 
the  inner  side  of  the  neck  on  the  lower  jaw.  It  then  passes  up  under 
the  parotid  gland,  and  along  with  the  temporal  artery  over  the  zygoma, 
and  divides  into  temporal  branches  to  the  skin  of  the  temporal  region, 
joining  the  facial.  This  nerve  communicates  at  its  origin  with  the  otic 
ganglion,  and  gives  oif  the  following  branches: 

Auricular^  the  inferior  to  the  external  meatus,  the  superior  to  the 
tragus  and  pinna. 

Articular^  one  or  two  to  the  articulation  of  the  jaw ;  several  to  the 
parotid^  and  the  branches  to  the  external  auditory  meatus  send  a  fila- 
ment to  the  membrana  tympani. 

The  inferior  dental  nerve  runs  along  with  the  artery,  enters  that 
canal,  supplies  the  teeth,  and  at  the  mental  foramen  divides  into  an  incisor 
and  a  mental  branch.  The  former  supplies  the  canines  and  incisors,  the 
latter  the  skin  of  the  chin  and  lower  lip.     The  nerve  is  at  first  under  the 


SUBMAXILLARY   AND   OTIC   GANGLIA.  271 

external  pterygoid ;  later,  between  the  ramus  of  the  jaw  and  the  internal 
lateral  ligament.  Its  branches  are  the  mylo-hyoid  and  dental.  The 
mylo-hyoid  runs  in  the  groove  to  supply  the  mylo-hyoid  and  anterior 
belly  of  digastric  muscles.  The  dental  supply  the  molars  and  bicuspids, 
interlacing  to  form  a  fine  plexus,  the  inferior  dental. 

The  gustatory  or  lingual  nerve  lies  at  first  beneath  the  external 
pterygoid,  internal  to  the  dental  nerve.  Here  a  branch  from  the  dental 
may  cross  the  internal  maxillary  to  join  it.  The  chorda  tympani  also 
joins  it.  The  nerve  now  runs  along  the  inner  side  of  the  ramus  of  the 
jaw,  and  crosses  the  upper  constrictor  to  the  side  of  the  tongue  above 
the  deep  part  of  submaxillary  gland ;  lastly,  it  runs  below  Wharton's 
duct,  and  superficially  along  the  side  of  the  tongue  to  its  apex.  It 
communicates  with  the  facial  through  the  chorda  tympani,  the  submax- 
illary ganglion,  inferior  dental,  and  hypoglossal.  It  supplies  the  mucous 
membrane  of  the  mouth  and  tongue  (anterior  two-thirds),  the  gums, 
sublingual  gland,  and  the  fihform  and  fungiform  papillae. 

Describe  the  submaxillary  ganglion. 

It  is  placed  above  the  deep  part  of  the  gland,  and  receives  filaments 
from  the  gustatory  and  from  the  inferior  maxillary  nerve  through  the 
chorda  tympani ;  also  filaments  from  the  sympathetic  plexus  around  the 
facial  artery. 

Branches:  Five  or  six  to  gland,  Wharton's  duct,  and  the  mucous 
membrane  of  the  mouth. 

Describe  the  otic  ganglion. 

It  is  of  a  reddish  color,  oval  and  flattened  in  form,  and  i  inch  in 
diameter.  It  lies  on  the  inferior  maxillary  nerve  (deep  surface)  below 
the  foramen  ovale,  and  behind  it  is  the  middle  meningeal  artery.  It 
communicates  with  the  inferior  maxillary  through  its  internal  pterygoid 
branch,  with  the  small  superficial  petrosal  nerve,  and  with  the  plexus  on 
the  middle  meningeal  artery. 

Branches :  One  to  the  tensor  tympani,  to  tensor  palati,  to  chorda 
tympani ;  and  to  the  auriculo-lemporal  nerve  two. 

Describe  the  sixth  nerve. 

*  The  sixth  or  abducens  has  an  apparent  origin  in  the  groove  be- 
tween the  pons  and  medulla,  and  a  deep  origin  from  the  fasciculus  teres. 
It  runs  to  the  lower  and  outer  part  of  the  dorsum  sellae,  and  traverses 
the  floor  of  the  cavernous  sinus  external  to  the  carotid  artery,  and,  re- 
ceiving branches  from  the  cavernous  and  carotid  plexuses,  enters  the 
orbit  by  the  sphenoidal  flssure  between  the  two  heads  of  the  external 
rectus;  it  receives  a  branch  from  the  ophthalmic  nerve,  and  suppHes 
the  above-named  muscles. 

What  are  the  relations  of  the  parts  in  the  cavernous  sinus  and 
sphenoidal  fissure? 
In  the  sinus:  the  third,  fourth,  and  the  ophthalmic  branch  of  the 


272  CRANIAL   NERVES. 

fifth  lie  in  the  outer  wall,  in  numerical  order  from  above  downward  and 
from  within  outward ;  with  the  sixth  nerve,  on  the  floor  and  external  to 
the  carotid  artery.  In  the  fissure:  the  fourth,  with  the  frontal  and 
lachrymal  divisions  of  the  ophthalmic,  lie  in  this  order  from  within  out- 
ward and  just  below  the  periosteum.  All  the  rest  enter  between  the 
heads  of  the  external  rectus  in  this  order  from  above  downward :  the 
upper  division  of  the  third ;  nasal  branch  of  the  fifth ;  lower  division 
of  the  third  ;  and  the  sixth.    ,The  ophthalmic  vein  is  below  them  all. 

Describe  the  seventh  nerve. 

The  seventh  or  facial  has  a  superficial  origin  from  the  depression 
between  the  olivary  and  restiform  bodies,  and  a  deep  from  the  fasciculus 
teres.  Between  it  and  the  eighth  is  the  pars  intermedia^  which  joins 
the  facial  in  the  auditory  canal.  The  nerve  runs  outward  to  the  internal 
meatus,  v^here  it  runs  in  a  groove  on  the  auditory  nerve,  enters  the  aque- 
ductus  Fallopii,  and  emerges  at  the  stylo-mastoid  foramen.  It  presents 
within  the  aqueduct,  near  the  hiatus  Fallopii,  a  reddish  enlargement,  the 
geniculate  ganglion.  Outside  the  cranium  it  runs  forward  in  the  parotid 
gland,  and  divides  behind  the  ramus  into  the  cervico-facial  and  temporo- 
facial  divisions.  In  the  parotid  and  vicinity  the  radiating  branches 
form  the  pes  anserinus. 

Communicating  branches:  In  the  internal  auditory  meatus,  one  or 
two  communicating  with  auditory  nerve. 

In  the  aqueduct  it  communicates  with  MeckeFs  ganglion  by  means  of 
the  large  superficial  petrosal;  with  the  otic  ganglion  by  a  small  branch 
to  the  small  superficial  petrosal;  with  the  sympathetic,  on  the  middle 
meningeal,  by  the  external  petrosal ;  and  with  the  pneumogastric  {auri- 
cular branch). 

Outside  the  cranium :  it  sends  branches  to  the  glosso-pharyngeal, 
carotid  plexus,  auricularis  magnus,  auriculo-temporal,  and  facial  nerves. 

Branches  of  distribution :  In  the  aqueduct :  a  tympanic  branch  to  the 
stapedius,  and  the  chorda  tympani.  The  latter  arises  close  to  the  stylo- 
mastoid foramen,  ascends  in  a  small  canal  to  the  posterior  wall  of  tym- 
panum, and  then  passes  over  the  upper  part  of  the  membrane  between 
the  handle  of  the  malleus  and  the  incus,  finally  emerging  through  the 
canal  of  Huguier ;  it  then  descends  on  the  inner  side  of  the  internal  lat- 
eral ligament  of  the  jaw,  and  joins  the  gustatory  nerve,  through  which 
its  fibres  reach  the  submaxillary  ganglion  and  lingualis  muscle.  It  re- 
ceives a  branch  from  the  otic  ganglion  before  joining  the  lingual. 

Outside  the  cranium :  the  posterior  auricular  ascends  between  the  ear 
and  the  mastoid,  receives  a  branch  from  the  vagus,  one  from  the  auricu- 
laris magnus,  and  one  from  the  occipitalis  minor,  and  divides  into  an 
auricular  branch  to  the  back  of  the  auricle  and  retrahens,  and  an  occip- 
ital branch  to  the  occipito-frontalis. 

The  digastric  branches,  to  the  posterior  belly  of  the  digastric,  one  join- 
ing the  glosso-pharyngeal  nerve ;  and  a  stylo-hyoid  branch  to  the  muscle, 
joining  the  carotid  plexus. 


THE   NINTH   NERVE.  273 

The  temporo-fadal  division  crosses  the  external  carotid  artery  and  the 
temporo-maxillary  vein  in  the  upper  part  of  the  parotid,  receives  fila- 
ments from  the  auriculo- temporal  nerve,  and  divides  into  three  sets  of 
branches — viz.  temporal,  malar,  and  infraorbital. 

The  temporal  branches  supply  the  attolens  and  attrahens,  occipito- 
frontalis,  orbicularis,  and  corrugator  supercilii.  They  communicate  with 
the  auriculo-temporal,  temporal  branch  of  superior  maxillary,  and  supra- 
orbital nerves. 

The  malar  branches  run  to  the  outer  angle  of  the  orbit,  supply  the 
orbicularis  and  corrugator,  joining  the  lachrymal  and  supraorbital,  and 
some,  to  lower  lid,  join  with  the  superior  maxillary  nerve  (palpebral 
branches). 

The  infraorbital  group,  to  the  space  between  the  orbit  and  mouth. 
They  supply  the  buccinator,  orbicularis  oris,  the  levator  labii  superioris, 
the  levator  anguli  oris,  and  nasal  muscles.  They  unite  with  the  cervico- 
facial branches,  the  nasal,  infratrochlear,  and  with  the  superior  maxillary 
nerve.     The  latter  forms  the  infraorbital  plexus. 

The  cervico-facial  division  descends  through  the  parotid,  joining 
branches  of  the  great  auricular,  and  divides,  near  the  angle  of  the  jaw, 
into  buccal,  supramaxillary,  and  inframaxillary  branches. 

The  buccal  cross  the  masseter,  supply  the  buccinator  and  orbicularis 
oris,  and  join  the  infraorbital  nerves  and  the  buccal  nerve  from  the  in- 
ferior maxillary. 

The  supramaxillary^  beneath  the  depressor  anguli  oris,  supplies  the 
inferior  labial  muscles,  and  joins  branches  of  the  inferior  dental. 

The  inframaxillary  pierces  the  deep  cervical  fascia,  supplies  the 
platysma,  and  forms  arches  in  the  suprahyoid  region,  joining  the  super- 
ficial cervical  nerve. 

Describe  the  auditory  nerve. 

The  eighth  or  auditory  is  the  special  nerve  of  the  sense  of  hearing. 
Superficially  it  appears  at  the  lower  border  of  the  pons,  external  to  the 
facial.  It  has  two  roots — one  from  the  inner  side  of,  and  one  from  the 
front  of,  the  restiform  body.  It  runs  to  the  internal  auditory  meatus 
with  the  facial  nerve,  the  two  being  separated  by  the  pars  intermedia 
and  the  auditory  artery.  The  nerve  in  the  meatus  divides  into  a  coch- 
lear and  a  vestibular  branch. 

Describe  the  ninth  nerve. 

The  ninth  or  glosso-pharyngeal  arises  superficially  by  several 
filaments  from  the  groove  between  the  olivary  and  restiform  bodies  at 
the  upper  part  of  the  medulla ;  deeply  through  the  lateral  tract  to  a 
gray  nucleus  in  the  floor  of  the  fourth  ventricle. 

The  nerve  runs  in  front  of  the  flocculus  to  pass  through  the  middle 
part  of  the  jugular  foramen  with  the  vagus  and  spinal  accessory,  in  a 
separate  sheath,  and  here  presents  two  successive  ganglionic  enlarge- 
ments, the  jugular  and  the  petrous  ganglia.  Outside  the  cranium  it 
IS— A. 


274  CRANIAL   NERVES. 

passes  between  the  jugular  vein  and  the  internal  carotid  artery,  descend- 
ing in  front  of  the  latter,  and  beneath  the  styloid  process  and  its  mus- 
cles, to  the  lower  border  of  the  stylo-pharyngeus.  It  then  crosses  this 
muscle  and  divides  into  branches  beneath  the  hyoglossus.  In  the  jugu- 
lar foramen  it  grooves  the  lower  border  of  the  petrous  portion  of  the 
temporal. 

The  upper  or  jugular  ganglion  is  of  small  size,  and  is  formed  in  the 
outer  part  of  the  nerve,  some  fibres  passing  over  but  not  joining  it. 

The  petrous  ganglion  is  larger,  and  lies  in  a  groove  in  the  petrous 
bone,  involving  the  entire  trunk  of  the  nerve.  From  it  pass  the  ti/m- 
panic  nerve  and  branches  of  communication  to  the  vagus  and  sympa- 
thetic. That  to  the  sympathetic  joins  the  upper  cervical  ganglion.  To 
the  vagus,  one  joins  its  auricular  branch  and  one  its  upper  ganglion. 
Another  branch  perforates  the  posterior  belly  of  the  digastric,  from  a 
point  just  below  the  petrous  ganglion,  to  join  the  facial  close  to  the 
stylo-mast oid  foramen. 

The  tympanic  (Jacobson's  nerve)  runs  in  a  canal  in  the  petrous  portion 
to  enter  the  tympanum  through  an  aperture  in  its  floor  close  to  the  inner 
wall,  and  divides  into  branches  which  groove  the  promontory  and  form 
the  tympanic  plexus.  It  gives  a  branch  to  the  fenestra  rotunda^  fenestra 
ovalis,  and  to  the  Eustachian  tube.  The  nerve  finally  emerges  from  the 
tympanum  by  a  canal  at  its  upper  and  back  part,  as  the  small  superficial 
petrosal  nerve.  This  latter  enters  the  cavity  of  the  skull  by  a  small  fora- 
men on  the  anterior  surface  of  the  petrous  portion  external  to  the  hiatus 
Fallopii,  and  escapes  by  a  small  foramen  in  the  great  wing  of  the  sphe- 
noid, sometimes  the  foramen  ovale,  to  join  the  otic  ganglion. 

The  tympanic  nerve  sends  a  communicating  branch  to  the  carotid 
plexus,  the  small  deep  petrosal. 

Branches  in  the  neck : 

The  carotid  branches  run  on  the  internal  carotid  to  its  commencement 
at  the  common  carotid,  joining  the  pharyngeal  branches  of  the  vagus 
and  the  sympathetic.  .   ^ 

The  pharyngeal,  three  or  four,  pierce  the  superior  constrictor  to  the 
mucous  membrane  of  the  upper  pharynx. 

The  muscular,  to  the  stylo-pharyngeus. 

The  tonsillitic,  to  the  tonsil  and  soft  palate,  form  the  circulus  tonsil- 
laris and  join  the  palatine  nerves. 

The  lingual  are  the  two  terminal  branches.  One  supplies  the  mucous 
membrane  of  the  posterior  third  of  the  tongue  and  the  circumvallate 
papillae ;  the  other,  to  the  side  of  the  tongue,  joins  the  gustatory. 

Describe  the  pneumogastric  nerve. 

The  tenth,  vagus,  or  pneumog'astric,  is  both  motor  and  sensory. 
Its  apparent  origin  is  by  twelve  to  fifteen  filaments  below,  and  in  the  line 
of  the  origin  of,  the  ninth  ;  its  deep  origin  is  from  a  nucleus  in  the  lower 
part  of  the  fourth  ventricle.  It  passes  through  the  jugular  foramen  in 
the  same  sheath  with  the  spinal  t^ccessory,  a  partition  separating  them 


THE   TENTH   NERVE.  275 

from  the  ninth,  and  develops  the  ganglion  of  the  root  of  the  vagus. 
Emerging  from  the  foramen,  it  forms  the  ganglion  of  the  trunk  of  the 
vagus. 

The  ganglion  of  the  root  (ganglion  jugulare)  is  gray  in  color  and 
spherical,  its  diameter  about  2  lines.  It  has  branches  of  communica- 
tion with  the  accessory  part  of  the  spinal  accessory,  with  the  petrous 
ganglion  of  the  ninth,  with  the  facial,  and  with  the  superior  cervical 
ganglion  of  the  sympathetic. 

The  ganglion  of  the  trunk  (ganglion  cervicale)  is  larger,  of  a  reddish 
color  and  cylindrical  form.  Its  surface  is  crossed  by  the  accessory  por- 
tion of  the  eleventh,  and  it  communicates  with  the  hypoglossal,  the 
upper  two  cervical,  and  the  sympathetic  nerves. 

The  vagus  then  descends  between  the  internal  carotid  artery  and  the 
jugular  vein  to  the  thyroid  cartilage,  then  between  the  vein  and  the 
common  carotid  to  the  root  of  the  neck. 

On  the  right  side  the  nerve  crosses  the  first  part  of  the  subclavian  artery, 
descends  behind  the  right  innominate  vein  and  alongside  of  the  trachea, 
and  spreads  out  into  the  posterior  pulmonary  plexus  behind  the  root  of  the 
lung.  Below,  two  cords  emerge  from  this  plexus  and  ramify  on  the 
oesophagus,  forming,  with  branches  from  the  left,  the  oesophageal  plexus. 
Again  forming  a  single  trunk,  the  nerve  descends  on  the  back  of  the 
oesophagus  to  ramify  on  the  posterior  surface  of  the  stomach. 

On  the  left  side  the  nerve  runs  behind  the  left  innominate  vein,  between 
the  left  carotid  and  subclavian  arteries,  and  crosses  the  arch  of  the  aorta. 
It  forms  the  left  posterior  pulmonary  plexus,  assists  to  form  the  oesopha- 
geal plexus,  and  as  a  single  trunk  descends  on  the  front  of  the  oesophagus 
to  ramify  on  the  anterior  surface  of  the  stomach. 

Branches:  [a)  In  the  jugular  foramen:  An  auricular  branch  (Ar- 
nold's), from  the  jugular  ganglion,  receives  a  branch  from  petrous  gan- 
glion of  the  ninth,  traverses  a  small  canal  in  the  petrous  portion  of  the 
temporal,  crosses  the  aqueductus  Fallopii,  and  communicates  with  the 
facial.  It  escapes  through  the  auricular  fissure,  then  divides  into  a  branch 
to  the  auricle,  and  a  second  which  joins  the  posterior  auricular.  A  re- 
current branch  from  the  jugular  ganglion  supplies  the  dura  mater  in  the 
posterior  fossa. 

^  {h)  In  the  neck :  A  pharyngeal  branch  from  the  cervical  ganglion,  de- 
riving its  fibres  mainly  from  the  spinal  accessory,  crosses  the  internal  car- 
otid, and  joins  with  glosso-pharyngeal  and  sympathetic  in  the  pharyngeal 
plexus.  This  plexus  supplies  the  muscles  and  mucous  membrane  of  the 
pharynx. 

The  superior  laryngeal^  from  the  lower  ganglion,  runs  internal  to  the 
internal  carotid  vessels,  receiving  branches  from  the  pharyngeal  plexus 
and  sympathetic,  and  divides  into  the  external  and  internal  laryngeal 
nerves. 

The  external  runs  beneath  the  sterno-thyroid  to  supply  the  crico-thy- 
roid.  It  supplies  the  inferior  constrictor,  and  sends  branches  to  the 
pharyngeal  plexus  and  superior  cardiac  nerve. 


276  CRANIAL   NERVES. 

The  internal  branch  pierces  the  thyro-hyoid  membrane  to  supply  the 
mucous  membrane  of  the  larynx,  and  by  a  long  branch  joins  a  similar 
offset  from  the  recurrent  nerve  behind  the  ala  of  the  thyroid  cartilage. 
A  twig  supplies  the  arytenoideus. 

The  inferior  or  recurrent  laryngeal  on  the  right  side  arises  in  front  of 
the  subclavian  arter}^  and  winds  backward  around  that  vessel;  on  the  left 
it  arises  in  front  of  the  arch  of  the  aorta  and  winds  backward  around  it. 
Both  nerves  ascend  between  the  trachea  and  oesophagus,  behind  the 
common  carotid  and  inferior  thyroid  arteries,  to  the  lower  border  of  the 
cricoid  cartilage.  They  enter  the  larynx  beneath  the  inferior  constrictor, 
supplying  all  its  intrinsic  muscles  excepting  the  crico-thjToid,  and  join 
the  superior  laryngeal.  Each  gives  oif  cardiac  nerves  which  join  those 
from  the  vagus  and  sympathetic ;  tracheal  and  oesophageal  branches,  and 
one  to  the  inferior  constrictor. 

The  cervical  cardiac  nerves,  two  or  three,  are  divided  into  the  superior, 
joining  the  cardiac  branches  of  the  sympathetic ;  and  the  inferior,  one 
on  each  side.  The  right  lies  in  front  of  the  innominate  artery,  and  joins 
the  deep  cardiac  plexus.  The  left,  in  front  of  the  arch  of  the  aorta, 
joins  the  superficial  cardiac  plexus. 

(c)  In  the  chest :  The  thoracic  cardiac  branches,  the  right  from  the 
trunk  0^  the  vagus  and  from  the  recurrent  branch,  the  left  from  the 
latter  only.     They  join  the  deep  cardiac  plexus.  ^ 

Pulmonary  nerves,  two  or  three  anterior,  join  the  sympathetic  and 
form  the  anterior  plexus  on  the  root  of  the  lung.  The  posterior,  larger 
and  more  numerous,  join  branches  from  the  second,  third,  and  fourth 
thoracic  ganglia  to  form  the  posterior  plexus.  Offsets  from  these  nerves 
accompany  the  bronchi  throughout  the  lung. 

The  oesoj)hageal.,  above  and  below  the  preceding.  The  lower  and 
larger  branches  come  from  the  oesophageal  plexus. 

(d)  Gastric  branches :  These  are  the  terminal  branches  of  the  vagi. 
The  right,  to  the  posterior  surface,  join  the  coeliac,  splenic,  and  left  renal 
plexuses.  The  left,  to  the  anterior  surface  and  lesser  curvature,  join  the 
right  nerve,  the  sympathetic,  and  the  hepatic  plexus. 

Describe  the  eleventh  pair. 

The  eleventh,  or  spinal  accessory,  consists  of  a  spinal  portion 
and  an  accessory  part  to  the  vagus.  The  latter  part  arises  as  five  or  six 
filaments  from  the  lateral  tract  of  the  medulla,  below  the  origin  of  the 
vagus.  It  sends  some  filaments  into  the  ganglion  jugulare  of  the  vagus, 
and  joins  that  nerve  below  the  ganglion  cervicale,  being  continued,  for 
the  most  part,  into  the  pharyngeal  and  superior  laryngeal  branches. 

The  spinal  portion  arises  from  the  lateral  column  of  the  cord  as  low  as 
the  sixth  cervical  nerve,  the  fibres  being  connected  with  the  anterior  horn 
of  gray  matter.  This  part  then  ascends,  between  the  posterior  nerve-roots 
and  the  ligamentum  denticulatum,  through  the  foramen  magnum,  then 
out  again  by  the  jugular  foramen,  lying  in  the  sheath  of  the  vagus,  and 
here  communicates  with  the  accessory  portion.     After  its  exit  from  the 


THE   SPINAL   NERVES.  277 

skull  it  crosses  the  internal  jugular  vein  and  pierces  the  sterno-mastoid 
to  end  in  the  trapezius. 

Describe  the  hypoglossal. 

The  twelfth  or  hypoglossal  nerve  arises  by  ten  to  fifteen  filaments 
from  the  groove  between  the  pyramid  and  olivary  body.  The  deep 
origin  is  from  a  nucleus  in  the  floor  of  the  fourth  ventricle.  The  filaments 
form  two  bundles  which  pierce  the  dura  separately  and  unite  in  the  an- 
terior condylar  foramen.  The  nerve  descends  behind  the  internal  carotid 
artery  and  internal  jugular  vein,  closely  bound  to  the  vagus,  then  passes 
forward  between  the  artery  and  vein,  and  becomes  superficial  below  the 
digastric,  curving  around  the  occipital  artery.  It  now  crosses  the  exter- 
nal carotid  and  lingual  arteries,  runs  between  the  mylo-hyoid  and  hyo- 
glossus,  communicates  with  the  gustatory  nerve,  and  after  piercing  the 
genio-glossus  breaks  up  into  filaments  to  the  substance  of  the  tongue. 

Branches  of  communication  pass  to  the  vagus,  superior  cervical  gan- 
glion of  sympathetic,  to  the  loop  between  the  first  and  second  cervical, 
and  to  the  gustatory  nerves. 

Branches  of  distribution : 

Descendens  noni  leaves  the  nerve  as  it  crosses  the  occipital  artery,  de- 
scends within  or  in  front  of  the  carotid  sheath,  and,  joining  the  communi- 
cantes  noni,  forms  a  loop  from  which  the  sterno-hyoid  and  thyroid  and 
both  bellies  of  the  omo-hyoid  are  supplied.  Its  origin  can  be  traced  to 
the  first  and  second  cervical  nerves. 

The  thyro-liyoid  branch  crosses  the  great  cornu  of  the  hyoid  bone,  to 
supply  the  muscle. 

Muscidar  branches  pass  to  the  stylo-glossus,  hyo-  and  genio-hyoglossus, 
and  genio-hyoid  muscles. 

Meningeal  branches  run  to  the  posterior  fossa,  leaving  the  nerve  at 
the  foramen. 

THE  SPINAL  NERVES. 

Name  and  describe  the  origin  of  the  spinal  nerves. 

The  spinal  nerves  consist  on  each  side,  of  eight  cervical,  twelve  dorsal, 
five  lumbar,  five  sacral,  and  one  coccygeal,  in  all  thirty-one  pairs,  which 
arise  from  the  cord  by  two  roots,  anterior  and  posterior.  The  latter  are 
the  larger  and  are  supplied  with  ganglia.  The  suboccipital  or  first  cervi- 
cal nerve  has  no  ganglion.  The  two  roots  unite  just  beyond  the  ganglion, 
and  the  resulting  trunk  divides  into  two  divisions^  anterior  and  posterior, 
each  containing  fibres  from  both  roots.  1l\\q posterior  division  divides  into 
an  external  and  an  internal  branch.  The  anterior  divisions  in  the  dorsal 
region  remain  separate,  but  elsewhere  they  unite  into  plexuses. 

Describe  the  posterior  divisions  of  the  cervical  nerves. 

That  of  the  first  or  siihoccipital  does  not  divide  into  an  external  and 
internal  branch.     It  crosses  the  atlas  to  the  suboccipital  triangle,  and 


278  THE   SPINAL   NERVES. 

supplies  the  complexus,  the  obliqui,  and  posterior  recti,  a  branch  joinini^ 
the  second  nerve.  Of  the  other  nerves,  the  external  branches  supply 
the  splenius,  transversaUs  coUi,  cervicahs  ascendens,  and  trachelo-mas- 
toid.  The  mte7mal,  except  that  of  the  second,  run  inward :  those  of 
the  third,  fourth,  and  fifth,  between  the  complexus  and  semispinalis, 
suppl}^  them  and  the  multifidus  and  the  skin  over  the  trapezius.  The 
internal  branches  of  the  sixth,  seventh,  and  eighth  run  beneath  the 
semispinahs,  and  supply  no  cutaneous  branches.  The  internal  branch 
of  the  second,  known  as  the  great  occipital  nea^ve^  pierces  the  trapezius 
and  complexus,  supplies  the  latter,  and  runs  with  the  occipital  artery 
supplying  the  back  of  the  head,  and  sends  a  branch  to  the  small  occipital. 

Describe  the  posterior  divisions  of  the  other  spinal  nerves. 

In  the  dor  sal  region  the  external  branches  increase  in  size  from  above 
downward,  pierce  the  lon^issimus  dorsi  to  supply  the  erector  spinas  group, 
and  those  of  the  lower  six,  the  skin.  The  internal  branches  of  the  six 
upper  supply  the  multifidus  and  semispinalis  dorsi  and  the  skin.  The 
six  lower  internal  supply  the  multifidus,  but  not  the  skin. 

In  the  lumbar  region  the  internal  branches  end  in  the  multifidus. 
The  external  supply  the  intertransverse  muscles  and  erector  spinas,  and 
the  upper  three  the  skin  over  the  gluteal  region. 

In  the  sacral  region,  of  the  upper  three,  the  internal  branches  end  in 
the  multifidus  spinas,  and  the  external  anastomose  with  the  fourth  sacral 
and  last  lumbar.  They  send  oiF  filaments  over  the  great  sciatic  ligament, 
finally  ending  in  the  skin  by  two  branches. 

The  last  two  do  not  divide,  but  join  the  coccygeal  nerve. 

The  posterior  division  of  the  coccygeal  nerve  ends  with  the  above,  and 
supplies  the  skin  over  the  coccyx. 

Describe  the  anterior  divisions  of  the  spinal  nerves. 

They  are  larger  than  the  posterior.  Each  division  is  connected  with 
the  sympathetic.  Those  of  the  cervical,  lumbar,  and  sacral  nerves  form 
plexuses.  Those  of  the  dorsal  nerves  for  the  most  part  remain  separate. 
(See  Brachial  Plexus. ) 

Describe  the  cervical  plexus. 

It  is  formed  by  the  anterior  divisions  of  the  upper  four  cervical  nerves, 
which  emerge  between  the  scalenus  medius  and  rectus  anticus  major. 
It  Res  upon  the  scalenus  medius  and  levator  anguli  scapulas,  beneath 
the  sterno-mastoid.  Each  nerve  except  the  first  divides  into  a  branch 
for  the  nerve  above  and  one  for  the  nerve  below.  The  anterior  division 
of  the  first  (suboccipital)  nerve  grooves  the  atlas  beneath  the  vertebral  ar- 
tery, and  joins  the  second,  supplying  the  rectus  lateralis  and  recti  antici. 
It  communicates  with  the  sympathetic,  vagus,  and  hypoglossal  nerves. 

What  are  the  branches  of  the  cervical  plexus  ? 
Its  branches  are  superficial  and  deep. 


PLATE  XXIII. 

Fig.  1.— To  face  page  27  8. 

RECT.  CAP  ,  LAT. 

i RECT. ANT.   MAJOR 
I  RECT.    ANT.     MINOR 

TO    SYMPATHETIC 


TO   SCALP  &  OCCIPITO   FRONTALIS 
TO  AURICLE 


AURICULAR 
FACJAL 


Plan  of  the  Cervical  Plexus. 


PLATE  XXIV. 

Fig.  1. — To  face  page  i 

.FROM  J^TS 


7RHOMBOID 

iSUS-CLAVIAM 


SUPRA-SCAPULAR 


C.  WITH  PHRJ 


BRS  TO  LONG^ 
LIS  COLLI  Sc 
SCALENI 


(ST  DORSAL 


EXr:    ANT:    THORACIC 

UPPER     SUB-SCAPULAA 

,SUB-SCAPULAR 
CIRCUMFLEX 


Plan  of  the  Brachial  Plexus. 


tHE   SPINAL   NERVES.  279 

The  superjidal  are  divided  into  ascending  and  descending. 

1.  Ascending  branches  : 

[a]  The  superficialis  colli,  from  the  second  and  third  nerves,  crosses 
the  sterno-mastoid,  and  divides  under  the  platysnia  into  two  branches, 
an  upper  and  a  lower,  which  ramify  in  the  skin  of  the  front  of  the  neck, 
from  the  maxilla  to  the  sternum. 

ih)  The  auricularis  magnus,  from  the  second  and  third,  runs  over 
the  sterno-mastoid  to  the  parotid  region,  and  supplies /acia/  branches  to 
the  skin  over  the  parotid,  a  mastoid  branch  to  the  skin  in  that  region, 
and  auricular  branches  to  the  lobule  and  back  of  the  auricle.  By  these 
branches  the  nerve  also  communicates  with  the  facial  and  small  occipital. 

(c)  The  occipitalis  minor,  from  the  second  and  third  (sometimes 
only  the  second),  runs  along  the  posterior  border  of  the  sterno-mastoid 
to  the  head  and  supplies  the  scalp.  It  communicates  with  the  great 
occipital  and  the  great  and  posterior  auricular  nerves,  and  gives  a  branch 
to  the  auricle. 

2.  Descending  branches  :  these  are  the  supraclavicular  nerves. 
They  arise  from  the  third  and  fourth  cervical,  and  divide  into  the  supra- 
sternal, supraclavicular,  and  supra-acromial  hranches,  which  descend 
between  the  trapezius  and  sterno-mastoid  to  supply  the  skin  over  the 
regions  indicated  by  their  names. 

The  deep  branches  consist  of  an  external  and  an  internal  series. 

The  EXTERNAL  include  muscular,  to  the  sterno-mastoid  (from  the 
second) ;  trapezius,  scalenus  medius,  and  levator  anguli  scapulae  (from 
the  third  and  fourth),  and  communicating,  which  join  the  spinal 
accessory  within  the  sterno-mastoid  and  trapezius,  and  also  between 
these  two  muscles. 

The  INTERNAL  are:  communicating,  from  the  loop  between  the 
first  and  second,  to  the  vagus,  hypoglossal,  and  sympathetic,  and  a 
branch  from  the  fourth  to  the  fifth ; 

Muscular,  to  the  lateral  and  anterior  recti  muscles  (from  the  first 
and  second); 

Communicantes  noni,  generally  two,  one  from  second  and  one 
from  third,  pass  under  or  over  the  internal  jugular  to  join  the  descend- 
ing branch  from  the  hypoglossal  nerve ; 

Phrenic,  from  the  third,  fourth,  and  fifth,  descends  on  the  scalenus 
anticus,  then  between  the  subclavian  artery  and  vein,  and  crosses  the 
internal  mammary  artery.  It  then  crosses  the  root  of  the  lung  and 
runs  between  the  pericardium  and  mediastinal  pleura  to  the  dia- 
phragm; it  communicates  with  the  sympathetic,  descendens  noni,  and 
the  nerve  to  the  subclavius.  The  right  is  deeper  than  the  left.  It 
runs  external  to  the  innominate  vein  and  superior  vena  cava.  The  left 
crosses  the  front  of  the  aortic  arch  and  the  left  vagus.  Both  phrenics 
supply  the  diaphragm,  pleura,  and  pericardium.  Filaments  from  the 
right,  with  the  phrenic  branches  of  the  solar  plexus,  form  a  ganglion 
which  sends  branches  to  the  suprarenal  capsules  and  inferior  vena  cava 
and  to  the  hepatic  plexus ;  on  the  left  side  there  is  no  ganglion. 


280  THE  SPINAL   NERVES. 

Describe  the  brachial  plexus. 

Formed  by  the  anterior  divisions  of  the  lower  four  cervical  and  first 
dorsal,  as  follows :  the  fifth  and  sixth  form  an  upper ;  the  seventh,  a 
middle ;  -and  the  eighth  cervical  with  first  dorsal  a  lower  trunk.  Each 
of  these  trunks  then  separates  into  an  anterior  and  a  posterior  branch. 

The  anterior  branches  of  the  upper  and  middle  trunks  form  the  outer 
cord  of  the  plexus ;  the  anterior  branch  of  the  lower,  the  inner  cord :  of 
the  posterior  cord  it  is  variously  stated  that  the  posterior  branches  of  all 
three  trunks  form  it,  or  that  the  posterior  branches  of  the  upper  and 
middle  trunks  form  it,  while  the  posterior  branch  of  the  lower  trunk 
joins  the  musculo-spiral  nerve.     It  is  altogether  a  matter  of  dissection. 

The  plexus  is  at  first  between  the  anterior  and  middle  scaleni,  then 
above  and  external  to  the  subclavian  artery.  It  passes  behind  the  clavicle 
and  subclavius,  lying  on  the  subscapularis  and  serratus  magnus.  The 
cords  lie  external  to  the  first  part  of  the  axillary  artery,  but  surround  the 
second  part  of  that  vessel. 

What  are  the  branches  of  the  brachial  plexus  ? 

Branches  above  the  Clavicle:  2i  branch  from  the  JiftJi  }oms  the 
phrenic,  and  muscular  branches  supply  the  scaleni,  longus  colli,  rhom- 
boidei,  and  subclavius.  The  branch  to  the  subclavius,  from  the  trunk 
formed  by  the  fifth  and  sixth  cervical,  crosses  the  subclavian  artery,  its 
third  part,  and  sends  a  branch  to  the  phrenic  nerve. 

The  posterior  thoracic  nerve  from  fifth  and  sixth  cervical  runs  out 
of  the  scalenus  medius  and  descends  behind  the  clavicle  upon  the  ser- 
ratus magnus,  which  it  supplies. 

The  suprascapular  nerve,  from  the  fifth  and  sixth,  enters  the  supra- 
spinous fossa  by  the  notch,  supplies  an  articular  branch  and  one  to  the 
muscle,  also  a  branch  to  the  infraspinous  fossa  and  muscle. 

Branches  below  the  Clavicle  :  the  three  cords  give  off  the  follow- 
ing nerves :  the  outer,  the  musculo-cutaneous,  outer  head  of  median,  ex- 
ternal anterior  thoracic ;  the  inner,  the  internal  anterior  thoracic,  inner 
head  of  median,  internal  and  lesser  internal  cutaneous,  and  the  ulnar; 
the  posterior,  the  musculo-spiral  and  circumflex  and  subscapular. 

Describe  the  thoracic  and  subscapular  nerves. 

The  anterior  thoracic  nerves  supply  the  pectoral  muscles.  The 
external  crosses  the  axillary  artery  and  gives  a  branch  to  the  inner  nerve, 
and  the  internal  runs  forth  between  the  artery  and  vein,  and  joins  the 
branch  from  the  external,  forming  a  loop  around  the  artery. 

The  subscapular  :  the  upper  supplies  the  subscapularis  at  its  upper 
part;  the  middle  or  long  accompanies  the  subscapular  artery  to  the 
latissimus  dorsi;  and  the  lower  supplies  the  subscapularis  and  teres 
major. 

Describe  the  internal  ** cutaneous"  nerves. 
The  internal  cutaneous,  on  the  inner  side  of  the  axillary  artery. 


THE   SPINAL   NERVES.  281 

divides  at  the  middle  of  the  arm  into  an  antrrior  branch,  crossing  over 
or  under  the  median  basihc  vein,  which  supphes  the  forearm  as  far  as 
the  wrist,  and  a  posterior,  which  winds  above  the  inner  condyle  to  back 
of  humerus,  and  runs  to  lower  part  of  forearm.  This  nerve  communi- 
cates with  the  lesser  nerve  and  the  ulnar,  and  supplies  the  skin  over  the 
biceps. 

The  lesser  internal  cutaneous  (of  Wrisberg)  runs  behind  and 
then  internal  to  the  axillary  vein  and  joins  the  intercosto-humeral  nerve. 
It  then  runs  along  the  inner  side  of  the  brachial  artery,  and  supplies  the 
skin  as  far  as  the  olecranon  and  internal  condyle. 

^  The  intercosto-humeral  bears  a  complementary  relation,  in  point  of 
size,  to  the  lesser  nerve,  and  may  even  replace  it  altogether. 

Describe  the  circumflex  and  musculo-cutaneous  nerves. 

The  circumflex  nerve,  behind  the  axillary  artery,  winds  back  through 
the  space  bounded  by  the  triceps,  humerus,  and  the  two  teretes  muscles, 
gives  a  filament  to  the  shoulder-joint,  and  divides  into  two  branches,  an 
upper  and  a  loioer.  The  former  winds  around  the  humerus  to  the  an- 
terior border  of  the  deltoid,  supplying  it  and  the  skin,  and  the  latter 
supplies  the  skin  over  the  lower  two-thirds  of  the  deltoid  as  well  as  the 
muscle,  and  gives  a  branch  to  the  teres  minor  upon  which  a  ganglion  is 
developed. 

The  external  or  musculo-cutaneous  nerve  arises  opposite  the  lower 
border  of  the  pectoralis  minor,  and  runs  through  the  coraco-hrachialu 
and  over  the  hrachialis  anticus  to  pierce  the  fascia  at  the  outer  border 
of  the  biceps.  It  then  runs  behind  the  median  cephalic  vein  and  divides 
into  two  branches,  anterior  and  posterior. 

In  the  arm  it  supplies  the  three  muscles  mentioned  above,  a  filament 
to  the  elbow-joint.,  and  one  to  the  humerus. 

The  anterior  branch  crosses  the  radial  artery  at  wrist  and  joins  a  branch 
of  the  radial  nerve  and  the  palmar  cutaneous  branch  of  the  median.  It 
supplies  the  skin  over  the  radius  and  twigs  to  the  artery.  The  posterior 
branch  descends  along  the  back  of  the  forearm  to  the  wrist  and  joins 
branches  of  the  radial  and  musculo-spiral  nerves. 

Describe  the  median  nerve. 

It  arises  by  two  roots,  an  outer  from  the  outer  cord  and  an  inner  from 
the  inner  cord,  which  unite  in  front  of  the  axillary  artery.  It  crosses 
over  (or  under)  the  brachial  artery  to  its  inner  side.  It  enters  the  fore- 
arm between  the  two  heads  of  the  pronator  teres,  running  on  the  flexor 
profundus  and  beneath  the  annular  hgament  into  the  hand.  At  the 
wrist  it  lies  behind  and  to  the  ulnar  side  of  the  palmaris  longus. 

Describe  its  branches. 

Branches:  in  the  arm,  none. 

In  the  forearm  li  supplies  all  the  superficial  flexor  muscles  except  the 
flexor  carpi  ulnaris ;  some  filaments  to  the  elbow-joint ; 


282  THE   SPINAL   NERVES. 

The  anterior  interosseous  nerve.  This  runs  along  the  interosseous 
membrane  with  the  artery  of  that  name.  It  supphes  the  flexor  longns 
pollicis  and  the  outer  half  of  the  flexor  profundus  digitorum  muscles, 
between  which  it  lies,  and  also  the  pronator  quadratus,  in  which  it 
ends. 

The  palmar  cutaneous  branch  pierces  the  fascia  above  the  annular 
ligament,  and  supplies  the  skin  over  the  ball  of  the  thumb  and  the  palm. 
It  communicates  with  branches  of  the  ulnar  and  external  cutaneous 
nerves. 

In  the  palm :  the  nerve  lies  on  the  flexor  tendons,  covered  by  the  an- 
nular ligament,  and  becomes  larger  and  reddish  in  color.  It  divides  into 
two  branches — the  external^  supplying  some  of  the  muscles  of  the  thumb 
and  digital  branches  to  the  thumb  and  index  finger ;  and  the  internal^ 
supplying  digital  nerves  to  the  index,  middle,  and  ring  fingers. 

The  musc}dar  branches  supply  the  abductor,  opponens,  and  outer  head 
of  the  flexor  brevis  pollicis.  ^hQ  first  digital,  with  the  second,  suppKes 
the  thumb,  the  former  joining  a  branch  of  the  radial.  The  thirds  along 
the  radial  side  of  the  index  finger,  supplies  it  and  the  first  lumbricalis. 
l^hQ  fourth  supplies  the  adjacent  sides  of  the  index  and  middle  fingers 
and  the  second  lumbricalis.  The  fifth,  to  the  adjacent  sides  of  the  middle 
and  ring  fingers  joins  a  branch  of  the  ulnar.  Each  digital  nerve  divides 
at  the  tip  of  the  finger  into  a  branch  to  the  pulp  and  one  to  the  matrix 
of  the  nail.  At  the  base  of  the  first  phalanx  each  sends  a  branch  to 
the  back  of  the  second  and  third  phalanges. 

Describe  the  ulnar  nerve. 

The  ulnar  runs  internal  to  the  axillary  and  brachial  arteries  as  far  as 
the  middle  of  the  arm.  It  then  passes  to  the  groove  between  the  olec- 
ranon and  internal  condyle  with  the  inferior  profunda  artery,  and  runs 
between  the  two  heads  of  the  flexor  carpi  ulnaris,  lying  beneath  the 
muscle  above  and  to  the  radial  side  of  it  below.  In  the  lower  two- 
thirds  of  the  forearm  the  ulnar  artery  is  external.  The  nerve  then 
crosses  the  annular  ligament  between  the  artery  and  pisiform  bone,  and 
divides  into  a  superficial  and  a  deep  branch. 

Describe  its  branches. 

Branches  :  In  the  arm,  none. 

In  the  forearm,  several  articular  to  the  elbow.  Muscular,  to  the 
flexor  carpi  ulnaris  and  inner  half  of  the  flexor  profundus.  Tico  cuta- 
neous, by  a  common  trunk.  One  joins  a  branch  of  the  internal  cuta- 
neous, and  the  other,  the  palmar  cutaneous,  runs  on  the  ulnar  artery  to 
the  palm,  joining  branches  of  the  median  nerve. 

The  dorsal  cutaneous  runs  backward  beneath  the  flexor  carpi  ulnaris, 
and  supplies  dorsally  the  little  and  inner  half  of  the  ring  finger.  The 
latter  communicates  with  the  contiguous  branch  of  the  radial. 

In  the  palm  :  the  superficial  and  deep  branches.  The  former  supplies 
the  skin  and  palmaris  brevis  and  digital  branches  to  the  little  and  inner 


THE   SPINAL   NERVES.  283 

half  of  the  ring  fingers,  the  latter  joining  a  branch  of  the  median.  The 
latter^  passing  iDetween  flex.  brev.  and  abductor  min.  digit. ,  supplies  all 
the  muscles  of  the  hand  except  those  supplied  by  the  median  nerve,  and 
sends  filaments  to  the  wrist-joint. 

Describe  the  musculo-spiral  nerve. 

It  runs  behind  the  axillary  and  brachial  vessels,  and,  later  in  the  mus- 
culo-spiral groove  with  the  superior  profunda  artery,  then  between  the 
brachialis  anticus  and  supinator  longus.  In  front  of  the  outer  condyle 
it  divides  into  the  radial  and  posterior  interosseous  nerves. 

Branches  :  muscular  and  cutaneous. 

Muscidar  branches:  the  internal  supplies  the  inner  and  middle  heads 
of  the  triceps;  the  posterior  supplies  the  outer  head  of  the  triceps  and 
the  anconeus;  the  external  supplies  the  supinator  longus,  extensor  carpi 
radialis  longior,  and  the  brachialis  anticus. 

Cutaneous  branches :  the  internal  supplies  the  inner  side  of  the  pos- 
terior aspect  of  the  arm ;  of  the  two  external,  the  upper  supplies  the 
lower  part  of  the  upper  arm  ;  -the  lower ^  the  lower  half  of  the  arm,  fore- 
arm and  wrist  dorsally,  joining  the  posterior  branch  of  the  musculo- 
cutaneous. 

Describe  the  radial  and  posterior  interosseous  nerves. 

The  radial,  beneath  and  parallel  with  the  supinator  longus,  finally 
runs  backward  beneath  its  tendon,  just  above  the  wrist,  pierces  the  fascia, 
and  divides  into  two  branches.  Of  these,  the  external  supplies  the  radial 
side  and  ball  of  the  thumb,  and  joins  a  branch  of  the  musculo-cutaneous ; 
the  internal,  after  communicating  with  the  musculo-cutaneous,  supplies 
dorsally  digital  branches  to  the  thumb  and  index,  index  and  middle, 
middle  and  outer  half  of  the  ring  fingers. 

This  last  joins  with  the  contiguous  branch  of  dorsal  cutaneous  of  ulna, 
and  they  all  terminate  at  base  of  second  phalanx. 

The  posterior  interosseous  pierces  the  supinator  brevis,  and  runs 
beneath  the  superficial  muscles  on  the  back  of  the  forearm  and  on  the 
lower  part  of  the  interosseous  membrane.  It  supplies  all  the  muscles 
of  the  back  and  outer  part  of  the  forearm  except  the  supinator  longus, 
extensor  carpi  radialis  longior,  and  the  anconeus,  and  terminates  at  the 
wrist  in  a  gangHon  from  which  are  supplied  the  carpal  ligaments  and 
joint. 

Describe  the  anterior  divisions  of  the  dorsal  nerves. 

First  dorsal:  the  anterior  division  in  part  joins  the  brachial  plexus, 
and  the  remainder  of  the  nerve  forms  the  first  intercostal,  which  has  no 
lateral  cutaneous  branch. 

The  upper  six  are  called  the  pectoral  intercostal  nerves,  and  lie  below 
the  vessels.  At  first  they  run  between  the  pleura  and  the  external  in- 
tercostal muscles,  then  between  the  two  planes  of  muscles  to  the  middle 
of  the  rib,  here  giving  off  the  lateral  cutaneovs  nerves.     The  nerves 


284  THE   SPINAL   NERVES. 

now  enter  the  substance  of  the  internal  intercostals  as  far  as  the  cartilages, 
where  they  lie  between  the  muscles  and  the  pleura.  Finally  they  cross 
the  internal  mammary  vessels  and  the  triangularis  sterni,  pierce  the 
internal  intercostals  and  pectoralis  major,  and  end  in  the  skin  of  the 
chest,  as  the  anterior  cutaneous  nerves  of  the  thorax. 

Branches :  muscular^  to  the  intercostals,  triangularis,  levatores  costa- 
rum,  and  serratus  posticus  superior. 

The  lateral  cutaneous  are  given  oiF  about  midway  to  the  sternum, 
pierce  the  serratus  magnus  and  external  intercostals,  and  each  divides 
into  two  branches,  anterior  and  posterior. 

The  anterior  runs  to  the  skin  over  upper  part  of  the  external  oblique, 
mamma,  and  skin ;  the  posterior^  to  the  skin  over  the  scapula  and  latis- 
simus  dorsi. 

The  lateral  cutaneous  of  the  second  dorsal  crosses  to  the  arm,  joins 
the  nerve  of  Wrisberg,  pierces  the  fascia,  and  supplies  the  skin  of  the 
upper  half  of  the  inner  and  back  part  of  the  upper  arm,  joining  the 
cutaneous  branch  of  musculo-spiral  nerve.  This  nerve  is  generally  called 
the  intercosto-humeral.     It  has  no  anterior  division. 

The  LOWER  SIX,  or  abdominal  intercostals,  run  from  the  intercostal 
spaces  behind  the  cartilages,  between  the  internal  oblique  and  transver- 
salis,  to  the  rectus,  which  they  enter.  They  supply  the  intercostals,  ser- 
ratus posticus  inferior,  abdominal  muscles,  and  end  in  the  skin,  as  the 
anterior  cutaneous  nerves  of  the  abdomen. 

The  lateral  cutaneous  branches  have  a  similar  distribution  to 
those  in  the  chest. 

The  LAST  DORSAL  nerve  is  altogether  abdominal.  It  crosses  the  quad- 
ratus  lumborum  and  runs  in  the  abdominal  wall  like  the  lower  inter- 
costals. It  communicates  with  the  ilio-hypogastric  and  with  the  first 
lumbar  nerve  [dorsi-lumhar).  Its  lateral  cutaneous  branch  supplies 
the  skin  of  the  forepart  of  the  gluteal  region  as  low  as  the  great  tro- 
chanter. 

Each  dorsal  nerve  is  joined  by  short  communicating  branches  from  the 
sj^mpathetic. 

Describe  the  anterior  divisions  of  the  lumbar  nerves. 

The  first  unites  with  a  branch  from  the  last  dorsal,  the  dorsi-lumhar 
nerve,  and  then  proceeds,  together  with  the  second,  third,  smd  fourth,  to 
form  the  lumbar  plexus.  The  fifth  joins  the  sacral  plexus.  They  are 
joined  by  sympathetic  filaments,  and  furnish  branches  to  the  psoas  and 
quadratus  muscles. 

Describe  the  lumbar  plexus. 

It  is  formed  in  the  substance  of  the  psoas  muscle,  in  the  following 
manner :  Each  of  the  first  four  lumbar  nerves  divides  into  an  tqyper  and 
a  lower  branch.  Just  before  dividing  the^r.s^  receives  the  dorsi-lumbar 
nen^e,  and  the  third  ?ind  foui-th  send  each  a  branch  to  the  nerve  below. 

The  upper  branch  of  the  first  subdivides  into  the  ilio-hypogastric  and 


THE  SPINAL   NERVES. 


285 


ilio-inguinal  nerves.  The  lowei'  branch  of  the  first  passes  downward 
and  subdivides  into  two  branches,  one  of  which  unites  with  the  upper 
branch  of  the  second  to  form  the  genito-crural  nerve.  The  other  unites 
with  the  loiver  branch  of  the  second  to  form  a  cord.  This  cord  passes 
downward,  and  gives  off  the  external  cutaneous  nerve  and  a  branch  to 
tlie  obturator,  after  which  it  unites  with  the  upper  branches  of  the  third 
and  fourth  to  form  the  anterior  crura!  nerve.  The  lower  branches  of  the 
third  and  fourth  unite  to  form  the  obturator  nerve.  (See  Fig.  15.) 

Fig.  15. 


OOliSILUMBRR  N. 


EXTCUTN 


08TURRTORN. 


Describe  the  ilio-hypogastric  and  ilio-inguinal  nerves. 

The  ilio-hypogastric  escapes  at  the  upper  part  of  the  psoas,  crosses 
the  quadratus,  pierces  the  transversahs  at  the  ihac  crest,  and  divides, 
between  it  and  the  internal  oblique,  into  two  branches.  The  iliac  branch 
supplies  the  skin  over  the  glutei,  behind  the  lateral  cutaneous  of  last 
dorsal ;  the  liypogaMric  branch  communicates  with  the  ilio-inguinal,  and 
pierces  the  oblique  muscles  to  supply  the  skin  of  the  pubic  and  hypo- 
gastric regions. 

The  ilio-inguinal  crosses  the  quadratus  and  iliacus  below  the  pre- 
ceding, pierces  the  transversalis,  communicating  with  the  ilio-hypogastric, 
and  runs  in  the  inguinal  canal,  supplying  the  skin  of  the  groin,  scrotum, 
and  penis  (the  labium  in  the  female). 

Describe  the  genito-crural  and  external  cutaneous  nerves. 
The  genito-crural  runs  downward  through  and  on  the  psoas  muscle, 


286  THE   SPINAL   NERVES. 

and  divides  some  distance  above  Poupart's  ligament  into  a  genital  and 
a  crural  branch.  The  former  lies  on  the  external  iliac  artery,  sendinjO^ 
filaments  around  it,  and  runs  with  the  cord  through  the  inguinal  canal 
to  the  cremaster  muscle ;  in  the  female  it  runs  on  the  round  ligament. 
The  crural  branch  runs  under  Poupart's  ligament  into  the  thigh,  send- 
ing filaments  around  the  femoral  artery,  and  lying  superficial  to  the  artery 
in  the  femoral  sheath.  It  supplies  the  skin  of  the  upper  thigh,  and 
joins  the  middle  cutaneous. 

The  external  cutaneous  crosses  the  iliacus  and  enters  the  thigh 
through  the  notch  below  the  anterior  superior  spine  of  the  ilium,  divid- 
ing into  an  anterior  and  a  posterior  branch.  The  fanner  runs  in  a  canal 
within  the  fascia  lata,  and  becomes  cutaneous  4  inches  below  Poupart's 
ligament.  It  supplies  the  front  and  outer  part  of  the  thigh  to  the  knee, 
sometimes  joining  in  the  patellar  plexus.  The  posterior  branch  supplies 
the  skin  of  the  outer  and  back  part  of  the  thigh  halfway  to  the  knee. 

Describe  the  obturator  nerve. 

The  obturator  nerve  emerges  from  the  inner  border  of  the  psoas  at  the 
pelvic  brim.  It  runs  above  the  obturator  vessels  to  escape  at  the  upper 
part  of  the  obturator  foramen,  dividing  into  two  branches  separated  by  the 
adductor  brevis.  The  anterior  runs  beneath  the  pectineus  and  adductor 
longus,  joining  at  the  lower  part  of  the  latter  with  branches  of  the  long 
saphenous  and  internal  cutaneous  nerves  to  form  a  plexus.  A  branch 
supplies  the  hip-joint ;  muscular  branches  to  gracilis  and  adductor  longus, 
sometimes  to  the  adductor  brevis  and  pectineus ;  the  terminal  branch 
to  the  femoral  artery. 

The  posterior  branch  pierces  the  obturator  externus  and  runs  behind 
the  adductor  brevis  on  the  adductor  magnus,  and  supplies  these  muscles. 
A  branch  to  the  knee-joint  pierces  the  magnus,  lies  on  the  popliteal  artery, 
sending  branches  to  it,  and  pierces  the  ligamentum  Winslowii  to  supply 
the  synovial  membrane. 

The  accessory  obturator  arises  by  branches  from  the  second,  third,  and 
fourth  nerves,  or  is  a  branch  of  the  obturator.  It  runs  along  the  inner 
border  of  the  psoas,  and,  crossing  the  pubes,  divides  beneath  the  pecti- 
neus into  three  branches — one  to  the  anterior  branch  of  the  obturator, 
another  to  the  hip-joint,  and  a  third  to  the  pectineus.     It  is  not  constant. 

Describe  the  anterior  crural  nerve. 

It  is  the  largest  branch  of  the  lumbar  plexus.  It  enters  the  thigh 
between  the  psoas  and  iliacus,  external  to  the  femoral  artery,  and  divides 
into. an  anterior  (mainly  cutaneous)  and  a  posterior  (mainly  muscular) 
portion. 

Branches :  • 

Within  the  abdomen,  three  or  more  branches  to  the  iliacus,  and  a 
branch  to  the  femoral  artery. 

Anterior  portion: 

(a)  The  middle  cutaneous  pierces  the  fascia  lata  4  inches  below  Pou- 


THE   SPINAL   NERVES.  287 

part's  ligament,  and  divides  into  two  branches  which  run  on  the  front  of 
the  thigh  to  the  patella.  It  joins  the  crural  branch  of  the  genito-crural 
and  the  internal  cutaneous  nerves. 

(b)  The  inteimal  cutaneous  crosses  the  femoral  artery  and  divides  into 
two  branches,  anterior  and  posterior.  It  supplies  several  cutaneous  fila- 
ments which  follow  the  course  of  the  long  saphenous  vein,  one  reaching 
to  the  knee.  The  anterior  branch  runs  to  the  knee,  perforating  fascia 
lata  low  down,  and,  crossing  the  patella  to  its  outer  side,  communicates 
with  a  branch  of  the  long  saphenous  nerve.  Th.Q  posterior  branch  runs 
along  the  posterior  border  of  the  sartorius,  communicates  with  the  in- 
ternal saphenous  nerve,  and  supplies  the  skin  of  the  inner  side  of  the 
thigh  (lower  part)  and  leg.  It  perforates  fascia  lata  at  inner  side  of 
knee.     It  also  joins  branches  of  the  obturator  beneath  the  fascia. 

[c\  Branch  to  the  pectineus  passing  behind  the  femoral  vessels. 
(d)  Branches  to  the  sartorius  from  the  middle  cutaneous. 
Posterior  Portion: 

[a)  Branch  to  the  rectus  femoris ;  also  sends  a  twig  to  the  hip-joint. 
{h)  Branch  to  the  vastus  externus. 

(c)  Branches  to  the  crureus:  one  of  these  sends  a  filament  to  the 
knee-joint. 

(d)  Branch  to  the  vastus  internus  accompanies  the  saphenous  nerve 
and  sends  a  filament  to  the  knee-joint. 

(e)  The  internal  saphenous  nerve  accompanies  the  femoral  vessels, 
being  at  first  external  to,  and  later  crossing,  the  artery.  It  then  runs 
beneath  the  sartorius  to  the  inner  side  of  the  knee,  pierces  the  fascia, 
and  accompanies  the  saphenous  vein  along  the  inner  side  of  the  leg. 
Passing  in  front  of  the  inner  ankle,  it  ends  on  the  inner  side  of  the 
metatarsus.  It  communicates  with  the  obturator  and  internal  cuta- 
neous. 

Branches  supply  the  skin  of  the  leg.  The  terminal  branches  commu- 
nicate with  the  musculo-cutaneous,  and  a  patellar  branch  spreads  out 
over  the  knee  and  joins  in  the  patellar  plexus. 

Describe  the  anterior  divisions  of  the  sacral  and  coccygeal  nerves. 

The  anterior  division  of  the  fifth  lumbar  receives  a  branch  from  the 
fourth,  and,  under  the  name  of  the  lumho-sacral  cord,  joins  the  first 
sacral. 

The  anterior  divisions  of  the  first  four  sacral  nerves  escape  by  the 
anterior  sacral  foramina ;  the  fifth,  between  the  sacrum  and  coccyx ;  all 
join  with  filaments  from  the  sympathetic. 

^  The  first  three^  with  a  branch  from  the  fourth,  enter  into  the  forma- 
tion of  the  sacral  plexus. 

The  fourth^  its  remaining  portion,  sends  branches  to  the  bladder  and 
adjacent  viscera,  and  supplies  the  levator  ani,  coccygeus,  external 
sphincter,  and  skin  of  the  perineum.  It  also  sends  a  branch  to  the  fifth 
sacral.  The  visceral  branches  unite  with  occasional  branches  from  the 
third  sacral  and  with  the  sympathetic. 


288  THE   SPINAL  NERVES. 

The  fifth  sacral  pierces  the  coccygeus,  supplying  it  and  the  skin  over 
the  coccyx.  Branches  from  the  fourth  sacral  and  the  coccygeal  nerve 
join  it. 

The  anterior  division  of  the  coccygeal  nerve,  very  small,  pierces  the 
coccygeus  and  sacro-sciatic  ligaments,  and  terminates  by  uniting  with  the 
fifth  sacral. 

Describe  the  sacral  plexus  and  enumerate  its  branches. 

It  is  formed  by  the  anterior  divisions  of  the  firsts  second,  thirds  and 
part  of  the  fourth  sacral  nerves,  together  with  the  lumbo-sacral  cord. 
The  lumbo-sacral  cord,  with  the  first,  second,  and  part  of  the  third 
sacral  nerve,  is  continued  into  the  upper  great  branch  of  the  plexus, 
and  the  remainder  of  the  plexus  forms  the  lower  or  smaller  branch. 

Branches  :  besides  these  two  principal  branches,  which  are,  respect- 
ively, the  great  sciatic  and  the  pudic  nerves,  the  upper  nerves  of  the 
plexus  give  off"  the  nerves  of  the  pyrifonnis^  guadratus  femoris,  obtu- 
rator interims,  and  gemelli,  as  well  as  the  superior  and  inferior  gluteal^ 
small  sciatic  J  and  a  perforating  cutaneous  branch. 

Describe  the  muscular  branches. 

The  muscular  branch  to  the  obturator  internus  crosses  the  spine  of  the 
ischium  and  enters  the  small  sciatic  foramen  to  the  inner  surface  of  the 
muscle.  It  also  supplies  the  superior  gemellus.  That  to  the  quadratus 
femoris  runs  beneath  the  tendon  of  the  obturator  internus,  and  supplies 
also  the  inferior  gemellus  and  hip-joint.  Lastly,  the  piriformis  receives 
several  filaments  from  the  sacral  nerves  previous  to  the  formation  of  the 
plexus. 

Describe  the  gluteal  nerves. 

The  superior  gluteal  emerges  above  the  pyriformis,  through  the 
great  sciatic  notch,  and  divides  into  an  upper  branch,  to  the  gluteus 
medius,  and  a  lower,  larger  branch,  which  supplies  both  the  medius  and 
minimus,  piercing  the  latter  to  end  in  the  tensor  vaginae  femoris.  It 
arises  from  the  lumbo-sacral  cord  and  first  sacral  nerve. 

The  inferior  gluteal  emerges  below  the  pyriformis,  dividing  into 
numerous  branches  for  the  gluteus  maximus.  It  sends  a  branch  to  join 
the  small  sciatic.  It  arises  from  the  lumbo-sacral  cord  and  first  and 
second  sacral  nerves. 

Describe  the  small  sciatic  and  perforating  cutaneous  nerves. 

The  small  sciatic  appears  below  the  pyriformis.  and  runs  beneath 
the  gluteus  maximus  upon  the  great  sciatic  nerve,  thence  beneath  the 
fascia  lata,  which  it  pierces  just  below  the  knee.  It  communicates  with 
the  external  saphenous  nerve.  It  arises  from  the  second  and  third 
sacral  nerves. 

Branches :  cutaneous,  to  the  calf  of  the  leg,  to  the  inferior  gluteal 
region,  and  to  the  back  and  inner  part  of  the  thigh  [femoral  cuta- 


THE   SPINAL   NERVES.  289 

neous) ;  and  the  inferior  'pudendal  nerve,  derived  below  the  tuber  ischii, 
to  the  scrotum  or  labium  majus  and  the  skin  of  the  upper  and  inner 
part  of  the  thigh. 

The  perforating  cutaneous  nerve,  from  the  fourth  sacral  nerve, 
pierces  the  great  sciatic  ligament  and  turns  over  the  lower  border  of  the 
gluteus  maximus  to  supply  the  skin  over  its  lower  part. 

Describe  the  pudic  nerve. 

The  pudic  nerve  emerges  between  the  coccygeus  and  pyriformis, 
and  crosses  the  ischial  spine  to  re-enter  the  pelvis  by  die  lesser  sacro- 
sciatic  foramen.  It  divides,  in  the  ischio-rectal  fossa,  into  the  inferior 
hemorrhoidal^  perineal^  and  dorsal  nerve  of  the  penis  vel  clitoridis. 

The  inferior  hemorrhoidal  mippWes  the  external  sphincter  and  the  skin 
of  the  back  part  of  the  perineum,  communicating  with  the  pudendal 
and  perineal  nerves. 

The  perineal  runs  in  a  sheath  of  the  obturator  fascia  along  the  outer 
wall  of  the  ischio-rectal  fossa,  and  divides  into  superficial  and  deep 
branches.  The  latter  supply  the  external  sphincter  and  the  muscles  of 
the  perineum,  sending  a  branch  to  the  mucous  membrane  of  the  urethra, 
which  pierces  the  corpus  spongiosum. 

The  superficial  branches  are  external  and  internal.  The  former  sup- 
plies the  scrotum  and  inner  side  of  the  thigh,  and  the  latter  runs  nearer 
to  the  middle  line  and  supplies  the  skin  of  scrotum.  Both  the  super- 
ficial perineal  nerves  communicate  with  the  pudendal  and  hemorrhoidal 
branches,  and  in  the  female  end  in  the  labia  majora. 

The  dorsal  ner've  of  the  penis  (in  the  female  of  the  clitoris)  accom- 
panies the  pudic  artery,  and  runs  along  the  dorsum  to  the  glans.  It 
supplies  branches  to  the  constrictor  urethras,  to  the  integument  of  the 
penis,  and  to  the  corpus  cavernosum.  On  the  penis  it  receives  branches 
from  the  sympathetic.  In  the  female  the  analogue  of  this  nerve  is 
smaller,  with  a  like  distribution. 

Describe  the  great  sciatic  nerve. 

This  is  the  largest  nerve  in  the  body,  and  includes  fibres  from  the 
greater  part  of  the  sacral  plexus.  From  the  lower  border  of  the  pyri- 
formis it  descends  on  the  gemelli,  obturator  internus,  and  quadratus, 
then  on  the  adductor  magnus,  being  covered  by  the  gluteus  maximus 
and  long  head  of  the  biceps,  and  accompanied  by  the  small  sciatic  nerve 
and  the  sciatic  artery.  It  divides  at  the  lower  third  of  the  thigh  into 
the  external  and  internal  popliteal  nerves.  It  supplies  the  biceps,  senii- 
tendinosus  and  semimembranosus,  adductor  magnus,  and  hip-joint. 

Describe  the  internal  popliteal  nerve. 

This  is  the  larger  branch  of  bifurcation  of  the  great  sciatic.     It  runs 
along  the  middle  of  the  popliteal  space  to  the  lower  border  of  the  pop- 
liteus,  where  it  becomes  the  posterior  tibial.     It  is  at  first  external  to, 
then  behind,  and  lastly  internal  to,  the  popliteal  artery, 
19— A, 


290  THE   SPINAL   NERVES. 

Branches:  three  articular^  one  accompanying  the  azj^gos  articular 
artery,  and  one  each  the  upper  and  lower  articular  arteries  on  the  inner 
side  of  the*  knee-joint. 

Muscular:  one  to  each  head  of  the  gastrocnemius,  to  the  plantaris, 
to  the  soleus,  and  to  the  popliteus.  The  latter  gives  filaments  to  the 
tibia  and  interosseous  membrane,  and  turns  beneath  the  lower  border 
of  the  muscle. 

Cutaneous :  the  external  or  sliort  saphenous  nerve,  or  tibial  communi- 
cating. ^  It  runs  between  the  two  heads  of  the  gastrocnemius,  pierces 
the  fascia  about  halfway  down  the  calf,  and  receives  the  peroneal  com- 
municating nerve  from  the  external  popliteal.  It  then  runs  in  company 
with  the  short  saphenous  vein,  along  the  outer  border  of  the  tendo 
Achillis  and  below  the  outer  malleolus,  to  end  in  the  skin  of  the  outer 
side  of  the  foot  and  little  toe,  communicating  with  the  musculo-cuta- 
neous  nerve. 

Describe  the  posterior  tibial  nerve. 

The  posterior  tibial  nerve  is  the  continuation  of  the  internal  popliteal 
from  the  lower  margin  of  the  popliteus.  It  is  successively  internal,  be- 
hind, and  external  to  the  artery,  and  divides  between  the  inner  ankle 
and  heel  into  the  two  plantar  nerves. 

Branches :  ai'ticidar,  to  the  ankle. 

Muscular :  one  each  to  the  tibialis  posticus,  flexor  longus  digitorum, 
flexor  longus  poUicis,  and  the  soleus. 

A  cutaneous  branch  pierces  the  internal  annular  ligament  to  supply 
the  skin  of  the  heel  and  back  part  of  the  sole. 

Describe  the  plantar  nerves. 

The  internal  plantar  nerve  runs  beneath  the  abductor  pollicis, 
then  between  it  and  the  flexor  brevis  pollicis,  and  divides  into  its 
digital  branches. 

Branches :  muscular,  to  the  abductor  pollicis  and  flexor  brevis  digi- 
torum. 

Cutaneous,  to  the  skin  of  the  sole. 

Digital  hrsiTiGhes  as  follows:  the  first,  to  the  inner  side  of  the  great 
toe,  supplies  the  flexor  brevis  pollicis ;  the  second,  to  the  great  and  sec- 
ond toes,  supplies  the  first  lumbricalis ;  the  third,  to  the  second  and  third 
toes,  supplies  the  second  lumbricalis ;  and  the  fourth,  to  the  third  and 
the  inner  side  of  the  fourth  toe,  communicating  with  the  external  plan- 
tar. ^  Each  digital  nerve  supplies  cutaneous  and  articular  branches  and 
terminates  as  in  the  hand. 

The  external  plantar  runs  between  the  flexor  accessorius  and  the 
flexor  brevis  digitorum,  dividing  between  the  latter  and  the  abductor 
minimi  digiti  into  a  superficial  and  a  deep  branch.  Before  dividing  it 
supplies  the  flexor  accessorius  and  abductor  minimi  digiti. 

The  superficial  gives  a  digital  branch  to  the  outer  side  of  the  little  toe, 
which  supplies  its  short  flexor  and  sometimes  also  the  interossei  of  the 


THE  SPINAL   NERVES.  291 

fourth  space,  and  another  digital  branch  to  the  adjacent  sides  of  this  toe 
and  the  fourth. 

The  deep  branch  dips  under  the  accessorius  and  flexor  muscles,  and 
supplies  all  the  dorsal  and  plantar  interossei  except,  occasionally,  those 
of  the  fourth  space ;  it  also  supplies  the  outer  two  lumbricales,  the  ad- 
ductor pollicis,  and  the  transversus  pedis. 

Describe  the  external  popliteal  nerve. 

The  external  popliteal  or  peroneal  nerve  runs  between  the 
biceps  muscle  and  outer  head  of  the  gastrocnemius,  turns  round  the 
fibula  below  its  head  and  beneath  the  peroneus  longus,  and  divides 
into  the  anterior  tibial  and  the  musculo-cutaneous  nerves. 

Brandies:  articular^  with  the  upper  and  lower  external  articular 
arteries,  and  occasionally  a  recurrent  articular  branch,  with  the  recurrent 
tibial  artery,  reaches  the  joint. 

Cutaneous^  two  in  number,  supply  the  skin  of  the  outer  and  back 
part  of  the  leg ;  and  another,  the  peroneal  commwiicating^  joins  the 
short  saphenous  nerve. 

Describe  the  musculo-cutaneous  nerve. 

The  musculo-cutaneous  nerve  runs  between  the  extensor  longus 
digitorum  and  the  peronei,  and  pierces  the  fascia  at  the  lower  part  of 
leg,  dividing  into  two  branches,  external  and  internal,  for  the  toes. 

Branches :  nmscidar,  to  the  peroneus  longus  and  brevis ;  cutaneous, 
to  the  lower  part  of  the  leg. 

The  terminal  branches :  of  these,  the  internal  runs  on  the  dorsum  of 
the  foot  and  supplies  the  adjacent  sides  of  the  second  and  third  toes  and 
the  inner  side  of  the  great  toe.  It  communicates  with  the  long  saph- 
enous and  anterior  tibial  nerves. 

The  external  supplies  the  fourth  toe,  together  with  the  contiguous 
sides  of  the  third  and  fifth.  It  communicates  with  a  branch  of  the 
short  saphenous  nerve. 

Describe  the  anterior  tibial  nerve. 

The  anterior  tibial  nerve,  from  between  the  peroneus  longus  and 
fibula,  runs  along  the  front  of  the  interosseous  membrane  with  the 
artery  to  the  ankle,  where  it  divides  into  an  external  and  an  internal 
branch.  It  is  at  first  external,  then  in  front,  and  below  again  external 
to  the  artery. 

Branches :  muscular,  to  the  tibialis  anticus,  extensor  longus  digitorum, 
extensor  proprius,  and  the  peroneus  tertius ;  articular,  to  ankle  ;  and  its 
terminal  branches.     Of  these — 

The  external  runs  under  the  extensor  brevis  digitorum,  and  supplies  it 
as  well  as  the  neighboring  joints. 

The  internal  accompanies  the  dorsal  artery  of  the  foot  to  the  first 
interosseous  space,  and  supplies  the  skin  of  the  great  and  second  toes, 
joining  a  branch  of  the  musculo-cutaneous.  Both  these  nerves  send 
interosseous  branches  to  the  metatarso-phalangeal  joints. 


292  THE   SYMPATHETIC   NERVOUS   SYSTEM. 

THE  SYMPATHETIC  NERVOUS  SYSTEM. 

Describe  the  general  arrangement  of  the  sympathetic  nervous 
system. 

The  sympathetic  nervous  system  consists  of  a  series  of  gangha,  cords, 
and  plexuses,  with  their  communicating  and  distributing  nerve-fibres. 
Its  nerves  supply  all  the  viscera  and  the  coats  of  the  blood-vessels. 

There  are  two  principal  gangliated  cords,  lying  one  on  each  side 
of  the  spine  from  the  base  of  the  skull  to  the  coccyx.  They  consist  of 
a  series  of  ganglia  connected  by  short  single  or  double  cords.  The  num- 
ber of  the  ganglia  corresponds  in  general  to  that  of  the  vertebrae  in  the 
several  regions,  except  in  the  neck,  where  there  are  but  three. 

Below,  these  cords  end  on  the  front  of  the  coccyx  by  a  loop  on  which 
is  the  ganglion  impar,  and  above  they  are  connected  with  the  carotid 
plexus  in  the  carotid  canal. 

The  ganglia  are  connected  with  the  spinal  nerves  by  gray  and  white 
fibres,  the  former  passing  from  the  ganglia  to  the  spinal  nerves,  and 
the  latter  vice  versa.  The  ganglia  are  also  connected  together  by  gray 
and  white  fibres,  the  latter  being  continuous  with  the  fibres  of  the  spinal 
nerves  prolonged  to  the  ganglia. 

There  are  three  great  plexuses,  consisting  of  nerves  and  ganglia. 
They  are  single  and  lie  in  front  of  the  spine  in  the  thoracic,  abdominal, 
and  pelvic  regions,  and  each  is  named,  from  above  downward,  the  car- 
diac, epigastric,  and  hypogastric  plexus. 

Describe  the  cervical  part  of  the  gangliated  cord  and  the  supe- 
rior cervical  ganglion. 

The  cervical  part  consists  of  three  ganglia,  named  superior,  middle, 
and  inferior,  on  each  side. 

The  superior^  opposite  the  second  and  third  cervical  vertebrae,  is  red- 
dish-gray in  color,  fusiform  in  shape,  and  lies  on  the  rectus  anticus  major 
behind  the  internal  carotid  vessels. 

Branches:  an  ascending  branch  runs  alongside  the  internal  carotid 
artery,  and  in  the  canal  separates  into  an  outer  division,  forming  the 
carotid  plexus,  and  an  inner,  forming  the  cavernous  plexus. 

The  carotid  plexus  lies  external  to  the  artery.  It  sends  one  or  more 
filaments  to  the  sixth  nerve  as  it  lies  alongside  the  artery,  and  some  to 
the  Gasserian  ganglion ;  to  the  spheno-palatine  ganglion  it  sends  the 
large  deep  petrosal  nerve,  which  joins  the  large  superficial  petrosal  to 
form  the  Vidian  ;  it  also  sends  the  small  deep  petrosal,  which  communi- 
cates with  Jacobson's  nerve  by  joining  the  tympanic  plexus. 

The  cavernous  plexus^  in  the  cavernous  sinus,  lies  below  and  internal 
to  the  internal  carotid.  It  sends  a  branch  to  the  third  nerve,  one  to  the 
fourth,  several  to  the  ophthalmic  division  of  the  fifth,  the  sympathetic 
root  to  the  ophthalmic  ganglion,  and  filaments  to  tlie  pituitary  body. 

Both  these  plexuses  supply  terminal  filaments  which  form  plexuses  on 
the  ophthalmic  and  cerebral  arteries  and  sub-branches : 


THE   SYMPATHETIC   NEEVOUS   SYSTEM.  293 

A  descending  branch  to  the  middle  cervical  ganglion. 

External  branches  to  the  first  four  spinal  nerves,  to  the  ganglia  of  the 
vagus,  the  petrous  ganglion  of  the  glosso-pharyngeal,  and  to  the  hypo- 
glossal. 

Three  internal  branches — viz.  pharyngeal,  laryngeal,  and  the  superior 
cardiac  nerve.  The  pharyngeal  runs  to  the  pharynx  and  unites  with 
the  branches  of  the  ninth  and  tenth  cranial,  forming  the  pharyngeal 
plexus. . 

The  laryngeal  branch  joins  the  superior  and  external  laryngeal  nerves. 

The  superior  cardiac  nerve  descends  on  the  longus  colli  behind  the 
common  carotid  sheath,  and  crosses  the  inferior  thyroid  artery  and  recur- 
rent nerve.^  It  rises  from  the  upper  ganglion,  and  receives  filaments  from 
a  communicating  branch  between  it  and  the  middle  ganglion.  On  the 
right  side  it  crosses  the  subclavian,  and  runs  along  the  innominate  artery 
to  join  the  deep  cardiac  plexus  behind  the  aorta.  It  receives  many 
branches  from  the  vagus  and  sympathetic.  The  left  descends  along  the 
left  carotid  to  enter  the  superficial  cardiac  plexus  in  front  of  the  aorta. 

The  anterior  branches  of  the  superior  ganglion  pass  to  the  blood-ves- 
sels— viz.  to  the  external  carotid  and  its  branches — forming  gangliated 
plexuses  named  lingual,  facial,  temporal,  meningeal,  etc.  They  com- 
municate with  the  submaxillary  and  otic  ganglia  and  with  the  geniculate 
ganglion  of  the  facial  nerve  [external petrosal  nerve). 

Describe  the  middle  cervical  ganglion. 

The  middle  (thyroid  ganghon)  lies  in  front  of  the  sixth  cervical  verte- 
bra, on  the  inferior  thyroid  artery.  It  is  connected  with  the  superior 
and  inferior  ganglia  and  with  the  fifth  and  sixth  cervical  nerves.  It  also 
gives  off  the  thyroid  branches  and  middle  cardiac  nerves. 

The  thyroid  branches  run  along  the  inferior  thyroid  artery  to  the 
gland,  and  join  the  recurrent  and  external  laryngeal  nerves.  On  the 
artery  they  connect  with  the  upper  cardiac  nerve. 

The  middle  cardiac  nerve  (deep  or  great),  on  the  left  side,  descends 
between  the  carotid  and  subclavian  arteries  to  join  the  deep  cardiac 
plexus ;  on  the  right  it  runs  in  front  of  or  behind  the  subclavian  artery, 
then  along  the  trachea,  to  join  the  deep  cardiac  plexus.  In  its  course 
it  joins  the  recurrent  branch  of  the  vagus  and  the  upper  cardiac  nerve. 

Describe  the  inferior  cervical  ganglion. 

It  lies  between  the  transverse  process  of  the  seventh  cervical  vertebra 
and  the  neck  of  the  first  rib,  behind  the  vertebral  artery,  and  commu- 
nicates with  the  seventh  and  eighth  cervical  nerves.  It  sends  branches 
to  the  middle  cervical  and  first  thoracic  ganglion  (these  branches  may  be 
derived  frona  the  middle  cervical  ganglion),  and  some  along  the  vertebral 
artery,  forming  a  plexus.  It  also  sends  off  the  inferior  cardiac  nerve. 
This  descends  behind  the  subclavian  artery  and  along  the  trachea,  and, 
after  communicating  with  the  middle  cardiac  and  recurrent  nerve,  ends 
in  the  deep  cardiac  plexus. 


294  THE   SYMPATHETIC   NERVOUS   SYSTEM. 

Describe  the  thoracic  portion  of  the  gangliated  cord. 

The  ganglia  lie  in  a  line  along  the  heads  of  the  ribs,  beneath  the 
pleura  and  in  front  of  the  intercostal  vessels.  They  communicate  with 
the  spinal  nerves.  The  upper  five  or  six  supply  the  aorta,  the  vertebrae 
and  their  ligaments,  and  enter  into  the  posterior  pulmonary  plexus. 

The  lower  six  or  seven  unite  to  form  the  splanchnic  nerves. 

Name  and  describe  the  splanchnic  nerves. 

The  great  splanchnic  arises  from  the  fifth  or  sixth  to  the  ninth  or 
tenth,  descends  obliquely  along  the  spine,  and  pierces  the  crus  of  the 
diaphragm  to  end  in  the  semilunar  ganglion,  sending  branches  to  the 
renal  plexus  and  suprarenal  capsule. 

The  small  splanchnic  arises  from  the  tenth  and  eleventh,  and, 
piercing  the  crus,  ends  in  the  coeliac  plexus,  communicating  with  the 
preceding  and  the  renal  plexus. 

The  smallest  splanchnic  arises  from  the  last  ganglion,  and  pierces 
the  crus,  joining  the  renal  plexus  and  sending  branches  to  the  coeliac 
plexus. 

Describe  the  lumbar  portion  of  the  gangliated  cord. 

The  lumbar  ganglia  lie  in  front  of  the  spine,  along  the  inner  side  of^ 
the  psoas.  They  communicate  with  the  ganglia  above  and  below,  and 
by  two  branches  with  each  of  the  spinal  nerves.  Branches :  some  cross 
the  aorta  to  join  the  aortic  plexus ;  some  cross  the  common  iliacs  and 
enter  the  hypogastric  plexus;  others  supply  the  vertebrae  and  their 
ligaments. 

Describe  the  sacral  portion  of  the  gangliated  cord. 

Over  the  sacrum  the  ganglia  lie  internal  to  the  anterior  sacral  foram- 
ina, sending  branches  to  the  ganglia  above  and  below,  and  two  branches 
each  to  the  sacral  nerves.  The  remaining  branches  join  together  and 
send  filaments,  some  to  enter  the  pelvic  plexus  and  others  to  form  a 
plexus  on  the  middle  sacral  artery.  The  two  lowest  ganglia  on  each 
side  are  joined  by  a  loop  over  the  coccyx,  on  which  is  the  ganglion 
inipar. 

Describe  the  cardiac  and  epigastric  plexuses  of  the  sympathetic. 

The  cardiac  plexus  lies  at  the  base  of  the  heart,  and  consists  of  a 
superficial  and  a  deep  part. 

The  superficial  cardiac  plexus  lies  between  the  aorta  and  the 
right  pulmonary  artery.  It  is  formed  by  the  left  superior  cardiac  nerve 
and  the  lower  cervical  cardiac  branch  of  the  left  vagus,  a  small  ganglion 
(Wrisberg's)  being  found  at  their  point  of  union.  It  forms  a  great  part 
of  the  right  coronary  plexus,  and  sends  filaments  to  the  anterior  pulmo- 
nary plexus.     It  receives  filaments  from  the  deep  cardiac  plexus. 

The  deep  cardiac  plexus  lies  between  the  trachea  and  the  aorta, 


THE   SYMPATHETIC   NERVOUS   SYSTEM.  295 

above  the  bifurcation  of  the  pulmonary  artery.  It  receives  all  the  car- 
diac branches  of  the  sympathetic,  excepting  the  left  superior  cardiac, 
and  of  the  vagus  and  its  recurrent  branch,  excepting  the  lower  cervical 
cardiac  branch  of  the  left  side. 

From  the  left  side  of  the  plexus  branches  pass  to  the  superficial  car- 
diac plexus  and  to  the  left  coronary  plexus.  From  the  right,  the 
branches  in  part  join  those  from  the  superficial  plexus  to  form  the  right 
coronary  plexus ;  some  pass  to  the  left  coronary  plexus,  others  to  the 
right  auricle.  Both  sides  of  the  plexus  furnish  filaments  to  the  ante- 
rior pulmonary  plexuses. 

The  left  coronanj  plexus  surrounds  the  left  coronary  arter}^  and  its 
branches,  and  supplies  the  cardiac  muscle.  The  right  suri'ounds  the 
right  coronary  artery  in  a  similar  way.  The  former  receives  its  filaments 
from  the  deep  plexus,  the  latter  from  both  superficial  and  deep. 

The  epigastric  (solar)  plexus  is  placed  in  front  of  the  aorta  and 
crura  of  the  diaphragm,  behind  the  stomach,  and  between  the  suprarenal 
bodies.  It  receives  the  great  splanchnic  nerves,  and  the  vagi  send 
branches  to  it.  It  consists  of  a  collection  of  nerves  and  ganglia,  and 
its  branches  accompany  the  vessels  to  the  principal  viscera  of  the  ab- 
domen. 

The  largest  of  its  ganglia  are  the  sein\hmai%  one  on  each  side.  They 
lie  near  the  suprarenal  bodies,  in  front  of  the  crura,  the  right  one  be- 
neath the  inferior  vena  cava.     They  receive  the  great  splanchnic  nerves. 

The  branches  of  the  solar  plexus  form  secondary  plexuses. 

Describe  these  secondary  plexuses. 

The  phrenic  plexns,  on  the  artery  of  the  same  name,  to  the  dia- 
phragm, supplies  also  the  suprarenal  capsules.  It  joins  with  branches 
from  the  phrenic  nerve,  and  at  the  point  of  junction  on  the  right  side 
is  a  small  ganglion,  the  diaphragmatic,  on  the  under  side  of  the  dia- 
phragm. 

The  suprarenal  plexus  receives  branches  from  the  phrenic  plexus 
and  great  splanchnic  nerves.  At  the  point  where  the  latter  join  is  a 
ganglion. 

The  renal  plexus  receives  filaments  from  the  aortic  plexus  and  the 
small  and  smallest  splanchnics.  The  branches  run  along  the  renal 
artery,  and  send  filaments  to  the  spermatic  plexus  and  to  the  inferior 
cava. 

The  spermatic  plexus  is  derived  from  the  renal  and  aortic  plexuses, 
and  runs  on  the  spermatic  vessels.  In  the  female  {ovarian)  it  supplies 
the  uterus  and  ovaries. 

The  celiac  plexus  surrounds  the  coeliac  axis,  and  divides  into  the  gas- 
tric, hepatic,  and  splenic  plexuses,  which  accompany  the  corresponding 
vessels.  It  receives  splanchnic  branches;  on  the  left  side  it  receives 
also  filaments  from  the  right  vagus. 

The  gastric  plexus  receives  filaments  from  the  vagi. 


296  THE   SYMPATHETIC   NERVOUS  SYSTEM. 

The  hepatic  plexus  receives  branches  from  the  left  vagus,  and  sends 
nerves  to  the  right  suprarenal  plexus,  and  forms  secondary  plexuses,  which 
follow  the  branches  of  the  hepatic  artery. 

The  splenic  plexus  is  reinforced  from  the  left  semilunar  ganglion  and 
the  right  vagus. 

All  the  above  plexuses  run  along  with  the  arteries,  and  subdivide  into 
secondary  plexuses,  corresponding  to  the  arterial  branches,  which  form 
complex  communications  with  one  another.  The  same  applies  to  the 
following : 

The  superior  mesenteric  plexus  is  reinforced  by  a  branch  from  the 
union  of  the  coeliac  axis  and  right  vagus. 

The  aortic  plexus,  on  the  abdominal  aorta,  is  reinforced  by  filaments 
from  the  solar  plexus  and  lumbar  ganglia,  renal  plexuses  and  semilunar 
ganglia.     It  ends  in  the  hypogastric  plexus. 

The  inferior  mesenteric  plexus  arises  from  the  preceding,  and  runs  on 
the  artery,  joining  superior  mesenteric  branches  and  the  pelvic  plexus. 

Describe  the  hypogastric  plexus. 

The  hypogastric  plexus  is  formed  by  lateral  prolongations  from 
the  aortic  plexus  and  lumbar  ganglia.  It  lies  between  the  two  common 
iliac  arteries.     Below  it  bifurcates  into  the  two  pelvic  plexuses. 

Describe  the  pelvic  plexuses. 

The  pelvic  plexuses  (inferior  hypogastric)  lie  one  on  each  side  of  the 
rectum,  and  in  the  female  the  vagina.  They  receive  filaments  from  the 
second,  third,  and  fourth  sacral  nerves,  and  where  these  join  the  plexus 
small  ganglia  are  developed.  The  nerves  from  the  plexus  supply  all  the 
pelvic  viscera,  accompanying  the  branches  of  the  internal  ihac  artery  and 
forming  secondary  plexuses. 

Describe  these  secondary  plexuses. 

The  hemorrhoidal  plexus  joins  the  superior  hemorrhoidal  branches 
(from  the  inferior  mesenteric  plexus)  to  suppl}^  the  rectum. 

The  vesical  plexus  contains  many  spinal  nerves,  runs  with  the  vesical 
arteries,  and  sends  nerves  along  the  vas  deferens. 

The  prostatic  plexus  consists  of  large  nerves  from  the  lower  part  of 
the  pelvic  plexus,  which  supply  the  prostate,  seminal  vesicles,  and  cav- 
ernous bodies.  These  latter  are  divided  into  the  small  and  large  cavern- 
ous, and  join  the  pudic  branches.  The  small  pierce  the  fibrous  coat  near 
the  root  of  the  penis  and  end  in  the  erectile  tissue.  The  large  (single) 
runs  forward  on  the  dorsum,  and  supplies  the  corpora  spongiosa  and 
cavernosa. 

The  vaginal  plexus  runs  in  the  vaginal  walls  and  mucous  membrane. 

The  uterine  plexus  sends  some  branches  along  the  uterine  artery,  and 
others  which  directly  pierce  the  cervix  and  lower  part  of  the  body. 
Branches  pass  also  to  the  ovarian  plexus  and  fundus  uteri. 


PLATE  XXV. 

Fig.  1.— To  face  page  ^97 . 


Canal  of  Schlemm. 


Posterior 
chamber. 

Ciliary 

body. 


Ciliary 
processes. 


Retina.' 


Choroid  coat. 


Canal  of 
Petit 


Canal  for 
"central  artery. 


Sclerotic  coat. 

Nerve  sheath. 


-Optic  nerve. 
Horizontal  Section  through  the  Left  Eyeball  (Allen). 


PLATE  XXVI. 

Fig.  1.  —  To  face  page  , 


Tncus. 

Malleus. 
I  \Stapes. 


-^^ Semi-circular  Canals. 

Vei 
Cochlea. 


A  Front  View  of  the  Organ  of  Hearing,  right  side. 
Fig.  2.— To  face  page  806. 


Floor  of  Scala  Media,  showing  the  Organ  of  Corti,  &c. 


ORGANS   OF  SPECIAL   SENSE.  297 

ORGANS  OP  SPECIAL  SENSE. 

THE   EYE. 
Give  a  general  description  of  the  eyeball. 

The  eyeball  lies  in  the  fat  of  the  orbit,  surrounded  by  a  tunic  of  fascia, 
the  capsule  of  Tenon.  It  is  composed  of  segments  of  two  spheres,  an 
anterior  smaller  and  a  posterior  larger,  the  junction  of  the  sclerotic  and 
cornea  indicating  their  limits.  It  measures  1  inch  transversely  and  ver- 
tically, and  somewhat  less  from  before  backward.  Behind  it  receives 
the  optic  nerve,  and  in  front  are  the  eyelids,  eyebrows,  etc. ,  which  com- 
prise the  so-called  appendages  of  the  eye. 

Describe  the  appendages  of  the  eye. 

These  include  the  eyebrows,  ej^elids,  conjunctiva,  the  lachrymal  gland 
and  sac,  and  the  nasal  duct,  the  last  three  belonging  to  the  "lachrymal 
apparatus." 

The  eyebrows  (supercilia)  are  two  prominent  tracts  of  integument  above 
the  orbit,  covered  by  thick  hairs.  They  are  connected  with  the  orbicu- 
laris, corrugator  supercilii,  and  occipito-frontalis  muscles. 

The  lids  (palpebrae)  protect  the  eyeball.  Each  is  composed  of  thin 
integument,  areolar  tissue,  muscular  fibres,  the  tarsal  cartilage  and  liga- 
ment. Meibomian  glands,  and  conjunctiva ;  the  upper  lid,  which  is  also 
the  more  movable,  contains,  in  addition,  the  aponeurosis  of  the  levator 
palpebrae. 

The  lids  are  separated,  when  opened,  by  a  space,  the  fissura  palpebra- 
rum, and  are  united  at  the  angles  (canthi).  The  outer  canthus  is 
sharp,  and  the  inner  is  more  obtuse.  At  the  inner  canthus,  on  each 
lid,  is  found  the  lachrymal  tubercle,  pierced  by  the  punctum  lachry- 
male,  the  upper  opening  of  the  lachrymal  canal. 

The  tarsal  cartilages  (tarsi)  are  two  plates  of  dense  fibrous  tissue,  one 
in  each  lid.  Into  the  anterior  surface  of  the  upper  the  levator  palpebrae 
is  inserted.  Each  is  attached  at  the  inner  angle  to  the  tendo  oculi  or 
internal  tarsal  ligament ;  at  the  outer  angle  to  the  external  tarsal  liga- 
ment, which  is  inserted  into  the  malar  bone. 

The  tendo  ocidi  or  palpebrarum  is  Y-shaped.  The  stem  is  attached  to 
the  nasal  process  of  the  superior  maxillary,  and  each  arm  to  one  of  the 
tarsal  cartilages. 

The  palpebral  ligament  is  a  fibrous  membrane  attached  to  the  tarsal 
cartilages  and  to  the  corresponding  margin  of  the  orbit. 

The  Meibomian  glands  lie  on  the  inner  surface  of  the  lids,  between 
the  tarsal  cartilages  and  the  mucous  membrane.  In  the  upper  lid  there 
are  about  thirty ;  in  the  lower,  fewer. 

The  lashes  (cilia)  are  short,  thick  hairs  forming  a  double  row  on  the 
free  margin  of  each  lid.     Above  they  are  longer  and  more  numerous. 

The  conjunctiva  is  the  mucous  membrane  of  the  e.ye.  The  palpebral 
portion  is  very  thick  and  vascular,  and  forms  at  the  inner  canthus  a  fold 


298  ORGANS   OF   SPECIAL   SENSE. 

known  as  the  plica  semilunaris.  The  ocular  portion  is  loosely  connected 
to  the  sclerotic,  but  over  the  cornea  consists  only  of  the  conjunctival 
epithelium.  The  line  of  reflection  from  the  lid  on  to  the  eyeball  is 
called  the  fornix  conjunctivae. 

Near  the  inner  canthus  there  is  also  a  collection  of  follicles  constituting 
the  caruncula  lachrymalis,  and  external  to  this  is  the  plica  semilunaris. 

Describe  the  lachrymal  apparatus. 

It  includes  the  gland,  the  two  canals,  the  sac,  and  the  nasal  duct. 

The  gland  is  about  the  size  and  shape  of  a  small  almond,  and  lies  in 
a  depression  in  the  orbital  plate  of  the  frontal  bone  just  inside  the  ex- 
ternal angular  process.  Above  it  is  attached  to  the  periosteum,  and  be- 
low it  rests  on  the  eyeball  and  the  upper  and  outer  recti.  In  front  it  is 
closely  connected  to  the  upper  lid  and  is  covered  by  conjunctiva.  Its 
ducts,  ten  or  more  in  number,  run  beneath  the  conjunctiva  and  open 
separately  at  the  outer  part  of  the  fornix. 

The  lachrymal  canals  commence  by  small  orifices,  the  puncta,  on  the 
margin  of  each  lid,  and  empty  close  together  into  the  sac.  The  upper 
and  longer  ascends  at  first,  then  runs  downward  and  inward ;  the  lower 
ones  downward,  then  inward. 

The  lachrymal  sac  is  the  upper  dilated  part  of  the  nasal  duct,  and  lies 
in  a  depression  formed  by  the  lachrymal  and  superior  maxillary  bones  ; 
it  is  invested  by  an  aponeurosis  derived  from  the  tendo  oculi,  and  is 
crossed  by  the  tensor  tarsi. 

The  nasal  duct  is  contained  in  a  canal  formed  by  the  superior  maxilla, 
lachrymal  and  inferior  turbinated  bones,  and  runs  from  the  lachrymal 
sac  to  the  inferior  meatus.  It  is  lined  by  a  mucous  membrane  continu- 
ous with  the  conjunctiva,  is  narrowest  in  the  middle,  and  at  its  lower 
expanded  orifice  is  the  valve  of  Hasner.  Its  direction  is  downward, 
backward,  and  outward.     Its  epithelium  is  ciliated. 

Describe  the  eyeball. 

The  eyeball  consists  of  three  coats  enclosing  the  refractive  media  or 
humors.  They  are  the  sclerotic  and  cornea  outside,  the  retina  internally, 
and  the  choroid  between  them. 

The  sclerotic  coat  is  a  dense  fibrous  membrane,  white  and  smooth 
externally,  excepting  where  it  receives  the  insertion  of  the  recti  and  ob- 
'  liqui.  Internally  it  is  brown,  grooved  by  the  ciliary  nerves,  and  united 
by  a  connective  tissue,  the  lamina,  fusca,  to  the  choroid  beneath.  It 
covers  the  posterior  five-sixths  of  the  eyeball.  Behind  it  receives  the 
optic  nerve  at  a  point  just  internal  to  the  centre,  the  fibrous  sheath  of  the 
former  being  continuous  with  the  sclerotic.  Here  there  is  a  number  of 
small  apertures  (lamina  cribrosa)  for  the  funiculi  of  the  optic  nerve,  and 
outside  of  these  smaller  foramina  for  the  passage  of  vessels. 

The  cornea  forms  the  anterior  sixth  of  the  external  coat.  It^  is 
transparent  and  projecting,  and  nearly  circular  in  shape,  the  anterior 
surface  being  convex  and  the  posterior  surface  concave. 


THE   EYE.  ,  299 

Describe  the  choroid  coat. 

The  second  or  intermediate  coat  is  continued  into  the  choroid,  pro- 
longed into  the  iris  anteriorly,  and  forming  the  ciHary  processes. 

It  is  a  chocolate-colored  vascular  structure  lying  between  the  sclerotic 

and  retina  and  investing  the  posterior  five-sixths  of  the  eyeball,  blending 

,  in  front  with  the  iris  after  forming  a  number  of  folds,  the  ciliary  processes. 

Behind  it  is  pierced  by  the  optic  nerve.     It  is  smooth  internally,  and  is 

connected  to  the  lamina  fusca  of  the  sclerotic  externally. 

The  ciliary  processes,  seventy  or  more  in  number,  consist  of  a  circle 
of  folds  or  thickenings  of  the  choroid  received  into  pits  in  the  vitreous 
and  suspensory  Hgament  of  the  lens.  They  are  divided  into  a  larger 
and  a  smaller  set,  the  former  being  about  ^  inch  in  length.  Their 
inner  surface  is  covered  by  the  layer  of  hexagonal  pigmented  cells  of 
the  retina. 

The  choroid  is  really  a  plexus  of  fine  blood-vessels.  Externally  it  pre- 
sents a  membrane,  the  lamina  siipraclioroidea^  between  which  and  the 
lamina  fusca  is  a  lymph-space  which  communicates  with  the  capsule  of 
Tenon  through  apertures  in  the  sclerotic. 

The  ciliary  muscle  is  a  circular  pkne  of  unstriped  muscle  placed  be- 
tween the  choroid  and  sclerotic  at  its  anterior  part.  It  consists  of  cir- 
cular and  radiating  fibres.  The  latter  arise  near  the  union  of  the  sclerotic 
and  cornea,  and  are  inserted  into  the  choroid  opposite  the  ciliary  pro- 
cesses ;  the  former  surround  the  insertion  of  the  iris. 

The  iris  gives  to  the  eye  its  color.  It  is  a  thin,  contractile,  circular 
membrane  presenting,  at  about  its  centre,  a  circular  aperture,  the  pupil. 
It  is  suspended  in  the  aqueous  humor  behind  the  cornea  and  in  front  of  the 
lens.  Its  circumference  is  continuous  with  the  choroid  and,  through  the 
ligamentum  pecfinatum,  with  the  cornea.  Its  posterior  surface  is  covered 
by  dark  pigment  resembling  that  of  a  ripe  grape ;  hence  the  term  ' '  uvea. ' ' 
The  edges  of  the  pupillary  orifice  are  in  contact  with  the  lens,  the  size 
of  the  pupil  varying  from  ^V  to  i  inch  across. 

The  muscle-fibres  are  radiating  and  circular.  The  latter  form  a 
sphincter  for  the  pupil;  the  former  constitute  the  dilator  muscle. 

Give  the  arterial  and  nervous  supply  of  the  iris. 

The  arteries  are  supplied  from  the  long  and  anterior  ciliary.  The 
nerves  are  branches  of  the  lenticular  ganglion  and  the  long  ciliary  from 
the  nasal  branch  of  the  ophthalmic.  They  form  a  plexus  around  the 
circumference  of  the  iris,  and  end  in  the  muscular  fibres  and  in  a  net- 
work on  the  front  of  the  iris.  The  nerves  to  the  circular  fibres  come 
from  the  motor  oculi ;  those  to  the  radiating,  from  the  sympathetic. 

Describe  the  retina. 

It  is  a  delicate  nervous  membrane  on  which  the  image  of  perceived 
objects  is  formed.  It  lies  between  the  choroid  and  the  hyaloid  mem- 
brane of  the  vitreous,  and  is  composed  of  ten  layers.  Behind,  the  optic 
nerve  expands  into  it,  and  in  front  it  terminates  in  a  dentated  margin, 


300  ORGANS  OF  SPECIAL  SENSE. 

the  ova  serrata^  at  tKecOuter  edge  of  the  cihary  processes.  It  then  sends 
oiF  a  thin,  non-nervous  membrane,  the  pars  ciliaris  retinae,  to  the  tips 
of  the  cihary  processes.  The  inner  surface  of  the  retina  presents  at  its 
centre  an  eUiptical  spot  about  ^V  i^^ch  across,  the  macula  lutea.  In  the 
centre  of  this  spot  is  a  depression,  the  fovea  centralis^  which,  on  account 
of  the  extreme  thinness  of  the  retina,  shows  the  pigmentary  layer  of 
the  choroid,  and  hence  presents  the  appearance  of  a  foramen.  About 
■^  inch  to  the  inner  side  of  the  yellow  spot  is  the  porm  opticus,  at  which 
point  the  optic  nerve  ejifers,  the  nervous  matter  being  heaped  up  here  so 
as  to  form  the  coUicuTus. 

What  are  Miiller's  fibres? 

Passing  through  nearly  the  entire  thickness  of  the  retina,  supporting 
its  layers  and  binding  them  together,  are  the  radiating  fibres,  or  fibres 
of  Mtiller.  They  form  at  one  extremity  the  membrana  hmitans  interna, 
and  at  the  other  the  externa. 

Describe  the  vitreous  body. 
The  vitreous  is  a  transparent  gelatinous  fluid  enclosed  in  a  trans- 

farent  membrane,  the  hyaloid,  and  fills  about  four-fifths  of  the  eyeball, 
n  front  it  is  hollowed  out  to  receive  the  lens  and  its  capsule,  being 
adherent  to  the  back  of  the  latter.  In  the  centre  of  the  vitreous  from 
the  entrance  of  the  optic  nerve  to  the  back  of  the  lens  runs  a  canal. 
It  contains  fluid,  is  about  xV  i^^ch  in  diameter,  and  is  called  the  canal 
of  Stilling. 

What  is  the  crystalline  lens? 

It  is  a  solid  transparent  biconvex  body  which  lies,  enclosed  in  its 
capsule,  in  front  of  the  vitreous  and  behind  the  iris.  The  greater  con- 
vexity is  behind,  and  the  lens  measures  antero-posteriorly  J,  transversely 
i,  inch.  It  consists  of  concentric  laminae  which  are  progressively  harder 
from  without  inward. 

The  capsule  is  an  elastic,  transparent,  structureless  membrane,  in  con- 
tact anteriorly  with  the  iris  and  held  in  place  by  the  suspensory  liga- 
ment. 

The  suspensory  ligament  is  a  thin,  transparent  membrane  placed  be- 
tween the  vitreous  humor  and  the  ciliary  processes,  and  presents  exter- 
nally a  number  of  folds  which  receive  those  of  the  ciliary  processes.  It 
is  really  a  part  of  the  hyaloid  membrane,  which  Tuns  forward  to  the 
front  of  the  margin  of  the  lens.  It  is  also  called  the  zonula  of  Zinn, 
and  is  covered  externally  by  the  pars  ciliaris  retinae.  Between  its  back 
part  and  the  lens  is  a  space,  the  canal  of  Petit.  This  canal  is  bounded 
in  front  by  the  suspensory  ligament  (zonula  of  Zinn),  behind  by  the 
vitreous,  and  at  its  base  is  the  capsule  of  the  lens. 

What  is  the  aqueous  humor? 

It  is  the  fluid  which  fills  the  space  between  the  suspensory  ligament 
and  capsule  behind  and  the  cornea  in  front.     That  part  of  this  space 


THE   EAR. 

which  lies  in  front  of  the  iris  is  called  the 
behind  the  iris  is  the  posteinor  chamber, 
small  interval  between  the  iris,  suspensory  ligj 
For  a  more  complete  description  of  the  eyj 

THE   BAR. 
Describe  the  ear. 

The  ear  is  divided  into  the  external  ear,  th 
and  the  internal  ear  or  labjTinth. 

Describe  the  external  ear. 

The  external  ear  includes  the  projecting  part,  or  phina,  and  the  external 
auditory  cayial  and  meatus.  The  pinna  or  auricle  is  concave  externally 
and  directed  somewhat  forward,  presenting  eminences  and  depressions  to 
which  various  names  have  been  given.  Thus,  the  most  external  ridge  is 
the  helix ;  parallel  and  internal  to  this  is  the  antihelix,  a  ridge  which 
divides  above  to  enclose  the  fossa  of  the  antihelix;  between  these  two 
ridges  is  \hQ  fossa  of  the  helix  (fossa  scaphoidea) ;  in  front  of  the  anti- 
helix  is  a  deep  depression,  the  concha^  which  presents  above  and  in  front 
"the  commencement  of  the  helix ;  in  front  of  the  concha  is  a  small  pro- 
cess, the  tragus^  which  points  backward ;  and  behind  this  is  the  anti- 
tragus,  a  deep  notch,  the  incisura  intertragica,  separating  the  two ;  and, 
lastly,  below  these  is  the  lobule. 

The  pinna  consists  of  a  plate  of  yellow  fibro-cartilage  covered  by  skin 
and  some  adipose  tissue.  It  enters  also  into  the  formation  of  the  exter- 
nal meatus,  being  attached  to  the  external  auditory  meatus  of  the  tem- 
poral bone.     The  lobule  contains  only  fat  and  strong  fibrous  tissue. 

The  external  auditory  canal  is  H  inches  long,  and  runs  from  the  con- 
cha to  the  membrana  tympani.  It  is  directed  somewhat  forward,  and 
presents  an  eminence  in  the  floor  of  the  osseous  part,  which  makes  the 
direction  of  the  canal  at  first  upward,  then  downward.  It  is  narrowest 
at  its  middle.  Its  floor  is  longer  than  the  roof,  on  account  of  the  ob- 
lique position  of  the  men)  bran  a  tympani.  It  opens  externally  by  means 
of  the  external  auditory  meatus. 

Describe  the  middle  ear  or  tympanum. 

The  tympanum  is  a  cavity  in  the  petrous  portion  of  the  temporal  bone, 
extending  from  the  membrana  tympani  to  the  outer  wall  of  the  labyrinth. 
Its  width  varies  from  t2^  to  J  inch.  It  contains  the  ossicles  of  the  ear, 
with  their  hgaments  and  muscles,  and  certain  nerves.  It  is  filled  with 
air,  and  communicates  by  means  of  the  Eustachian  tube  with  the 
pharynx. 

The  roof  of  the  tympanum  is  formed  of  very  thin  bone,  which  sepa- 
rates it  from  the  cranial  cavity.  The^oor  is  also  of  bone,  and  separates 
it  from  the  jugular  fossa  beneath  and  the  carotid  canal  in  front.  The 
outer  wall   is  formed  by  the  membrana  tympani  and  the  ring  of  bone 


302  ORGANS   OF   SPECIAL   SENSE. 

into  which  this  is  inserted,  and  presents,  just  in  front  of  the  bony  ring, 
the  Grlaserian  fissure,  which  lodges  the  processus  gracihs  of  the  malleus 
and  transmits  some  tympanic  vessels ;  at  the  back  part,  the  iter  posterius 
for  the  entrance  of  the  chorda  tympani,  and  the  iter  anterius,  anteriorly, 
for  its  exit.  The  former  leads  to  the  aqueductus  Fallopii,  the  latter  to 
the  canal  of  Huguier. 

The  membrana  tympani  is  a  thin  membrane  inserted  into  a  ring  of 
bone  at  the  bottom  of  the  external  canal,  which  is  grooved  for  its  recep- 
tion. It  is  ovoid  in  form  and  directed  obliquely  downward  and  inward. 
On  its  inner  surface  is  the  handle  of  the  malleus,  which  extends  to  a  little 
below  its  centre,  covered  by  mucous  membrane  where  it  is  attached.  This 
process  draws  the  membrane  inward,  making  its  outer  surface  concave  and 
its  inner  convex.  Externally,  the  membrane  is  covered  with  skin  con- 
tinuous with  that  of  the  meatus ;  internally,  with  mucous  membrane 
continuous  with  that  of  the  tympanum;  and  between  these  two  is  a 
fibrous  layer,  some  of  its  fibres  radiating  from  the  handle  of  the  malleus, 
others  being  circular  and  placed  near  the  circumference.  At  the  antero- 
superior  part  of  the  membrane  is  a  notch  in  the  bony  ring,  the  notch  of 
Rivini.  That  part  of  the  membrane  occupying  it  is  called  the  mem- 
brana flaccida. 

The  inner  wall  of  the  tympanum  is  vertical  and  uneven.  It  presents 
the  following :  {a)  The  fenestra,  ovalis^  leading  into  the  vestibule,  and 
occupied  in  the  recent  state  by  the  base  of  the  stapes  and  its  annular 
ligament.  (6)  Fenestra  rotunda^  in  a  conical  fossa  leading  into  the  coch- 
lea, a  rounded  eminence,  (c)  the  promontorij,  separating  it  from  the  pre- 
ceding. It  is  closed,  in  the  recent  state,  by  the  membrana  tympani  se- 
cundaria. This  is  composed  of  three  layers,  and  is  concave  toward  the 
tympanum.  The  middle  laj^er  is  fibrous,  the  outer  and  inner  being  con- 
tinuous with  the  lining  membrane  of  the  two  cavities.  The  promon- 
tory indicates  the  first  turn  of  the  cochlea,  and  is  grooved  for  branches 
of  the  tympanic  plexus,  {d)  The  ridge  of  the  aqueductus  Fallopii,  run- 
ning above  the  fenestra  ovalis  and  descending  on  the  posterior  wall,  (e) 
The  pyramid,  a  hollow  eminence  containing  the  stapedius,  the  tendon  of 
the  muscle  escaping  through  a  foramen  in  its  summit.  A  minute  canal 
containing  the  nerve  to  this  muscle  runs  from  the  aqueductus  Fallopii  to 
the  cavity  of  the  pyramid. 

The  posterior  ivall  of  the  tympanum  presents  above  one  large  and 
several  small  apertures  leading  to  the  mastoid  cells. 

The  anterior  eoctremity  opens  into  two  canals  separated  by  a  process  of 
bone,  the  processus  cochleariformis.  The  upper  of  these  canals  is  the 
smaller  and  transmits  the  tensor  tympani ;  the  lower  contains  the  Eusta- 
chian tube,  an  osseo-cartilaginous  passage  li  inches  long,  leading  to  the 
pharynx.  Both  of  these  canals  run  in  a  direction  downward,  forward, 
and  inward. 

The  osseous  part  of  the  Eustachian  tube  is  J  an  inch  long,  and  to  its 
lower  end  is  attached  the  triangular  piece  of  fibro-cartilage  forming  the 
remainder  of  the  tube.     The  edges  oi'  the  cartilage  are  not  in  contact, 


THE   EAR.  303 

but  are  joined  by  fibrous  tissue.  The  tube  is  wide  at  its  lower  extremity, 
and  opens  at  the  upper  and  lateral  part  of  the  pharynx,  above  the  hard 
palate  and  behind  the  lower  turbinated  bone.  It  is  hned  by  epithelium 
continuous  with  that  of  the  pharynx. 

Describe  the  ossicula. 

These  are  three  small  movable  bones,  named  the  malleus,  incus,  and 
stapes.  The  first  is  attached  to  the  membrana  tynipani ;  the  second  is 
between  the  other  two ;  the  last-named  is  attached  to  the  fenestra  ovalis. 

The  malleus  (a  hammer)  consists  of  a  head,  neck,  and  three  processes 
— viz.  the  processus  gracilis^  the  processus  hrevis,  and  the  mamihrinm. 
The  head  articulates  with  the  incus.  The  neck  is  below  it,  and  rests  on 
a  prominence  which  is  connected  with  the  three  processes.  The  ma- 
nuhrium  tapers  to  its  extremity,  which  is  flattened,  and  it  is  connected 
with  the  membrana  tympani.  The  tensor  tympani  is  attached  to  its 
inner  side  near  its  upper  end,  and  from  its  root  springs  the  processus 
hrevis.  The  processus  gracilis  is  long  and  slender,  and  is  connected  by 
bone  and  fibrous  tissue  with  the  Glaserian  fissure. 

The  incus  (an  anvil)  has  a  body  and  tico  processes.  The  hody  pre- 
sents a  saddle-shaped  articular  surface  for  the  malleus ;  the  short  process 
is  conical,  looks  backw^ard,  and  is  attached  to  the  opening  which  leads  to 
the  mastoid  cells ;  the  long  process  descends  behind  the  manubrium  of 
the  malleus,  to  end  in  the  os  orhicidare^  or  lenticular  process,  which  articu- 
lates with  the  head  of  the  stapes. 

The  stapes  (a  stirrup)  presents  a  head,  which  articulates  with  the  os 
orbiculare ;  a  neck^  to  which  is  attached  the  stapedius  muscle ;  and  two 
crura,  diverging  from  the  neck,  and  connected  at  their  extremities  by  the 
base,  which  fills  up  the  fenestra  ovalis. 

Describe  the  ligaments  of  the  ossicula. 

The  articulations  between  the  several  bones  are  provided  with  synovial 
membranes ;  their  surfaces  are  covered  with  cartilage  and  are  connected 
by  capsular  ligaments.  The  following  ligaments  connect  the  bones  with 
the  walls  of  the  tympanum  : 

The  anterior  ligament  of  the  malleus  is  attached  to  the  neck  of  the 
malleus  at  one  end,  and  at  the  other  to  the  anterior  wall  of  the  tympanum 
close  to  the  Glaserian  fissure,  and  its  suspensory  ligament  runs  from  the 
roof  of  the  tympanum  to  the  head  of  the  bone.  An  external  ligament 
runs  from  the  notch  of  Rivini  to  the  body  and  lesser  process,  and  the 
accessoi^  anterior  ligament  is  the  thickened  front  portion  of  the  sheath 
of  the  tensor  tjmipani.  which  runs  from  the  anterior  wall  to  the  manu- 
brium and  neck.  An  inferior  ligament  runs  from  the  end  of  the  handle 
to  the  outer  wall  of  the  tympanum. 

The  base  of  the  stapes  is  fixed  to  the  margin  of  the  fenestra  ovalis  by 
^an  annular  ligament. 

The  incus  is  provided  with  a  posterior  ligament,  running  from  the 


304  ORGANS   OF  SPECIAL   SENSE. 

short  process  to  the  posterior  wall,  and  a  suspensory  ligament^  from  the 
roof  of  the  tympanum  to  the  upper  part  of  the  bone  near  its  articulation 
with  the  malleus. 

Describe  the  muscles,  mucous  membrane,  vessels,  and  nerves  of 
the  tympanum. 

The  tensor  tympani  runs  in  the  canal  previously  mentioned.  Aris- 
ing from  the  under  surface  of  the  petrous  portion,  the  cartilage  of  the 
Eustachian  tube,  and  the  margins  of  its  own  canal,  its  tendon  is  reflected 
over  the  processus  cochleariformis  and  is  inserted  into  the  handle  of  the 
malleus  near  its  root.  It  pulls  on  the  malleus,  thus  drawing  inward  and 
making  tense  the  membrana  tj^mpani.  Its  nei^e  comes  from  the  otic 
ganglion. 

The  stapedius  arises  from  the  sides  of  its  containing  cavity  within 
the  pyramid,  and,  emerging  from  the  apex,  is  inserted  into  the  neck  of 
the  stapes.  It  draws  the  head  of  the  stapes  backward,  thus  pressing 
the  base  against  the  fenestra  ovalis  and  compressing  the  contents  of  the 
vestibule.     Its  nerve  is  the  tympanic  branch  of  the  facial. 

The  mucous  membrane  of  the  tympanum  is  pale  and  thin  and  its 
epithelium  ciliated.  It  invests  the  contents  of  the  cavity,  the  inner  sur- 
face of  the  membrana,  and  covers  the  fenestra  rotunda.  It  is  continuous 
with  that  of  the  mastoid  cells.  Eustachian  tube,  and  pharynx. 

The  tympanic  arteries  come  from  the  internal  maxillary,  the  stylo- 
mastoid branch  of  the  posterior  auricular,  the  petrosal  branch  of  the 
middle  meningeal,  the  Eustachian  branch  of  the  ascending  pharyngeal, 
and  from  the  internal  carotid.  The  veins  reach  the  internal  jugular  by 
means  of  the  middle  meningeal  and  pharyngeal  veins. 

The  nerves  of  the  tympanum  are  the  muscular^  already  men- 
tioned ;  the  nerves  to  the  mucous  irnemhraiie  from  the  tympanic  plexus ; 
the  commumcating,  viz.  between  Jacobson's  nerve,  the  sympathetic,  and 
branches  of  the  geniculate  ganglion  of  the  seventh;  and  the  chorda 
tympani. 

Jacohsons  nerve  (tympanic  branch  of  the  ninth)  enters  the  tympanum 
in  the  floor  and  passes  to  the  promontory.  It  forms  the  tympanic 
plexus,  from  which  are  supplied  the  fenestrae,  Eustachian  tube,  and 
lining  membrane,  and  sends  off"  two  commun-icating  branches:  one  to 
the  carotid  plexus,  one  to  the  great  superficial  petrosal.  It  then  receives 
a  filament  from  the  geniculate  ganglion  of  the  facial,  and  proceeds  to  join 
the  otic  ganglion  as  the  lesser  superficial  petrosal  nerve. 

The  chorda  fympam  ?ir\ses  from  the  facial  near  the  stylo-mastoid  fora- 
men, enters  at  the  base  of  the  pyramid,  crosses  the  tympanum  between 
the  long  process  of  incus  and  handle  of  malleus,  and  runs  through  the 
iter  chordae  anterius  to  the  canal  of  Huguier. 

Describe  the  internal  ear. 

This  is  the  essential  part  of  the  hearing  apparatus,  since  liere  the 
auditory  nerve  is  distributed.     It  is  contained  in  a  cavity  in  the  petrous 


THE   EAR.  305 

bone,  and  is  made  up  of  the  osseous  labyrinth  and  the  membranous 
labyrinth. 

Describe  the  osseous  labyrinth. 

The  osseous  labyrinth  contains  the  membranous  labyrinth,  and  is 
divided  into  three  parts,  the  vestibule,  semicircular  canals,  and  cochlea. 
It  communicates  in  the  dry  state  with  the  tympanum  by  means  of  the 
fenestrse.  Between  the  osseous  and  membranous  labyrinth  is  a  space 
occupied  by  a  clear  fluid,  the  perilymph,  and  within  the  membranous 
labyrinth  is  the  endolymph. 

The  vestibule  is  the  central  cavity  lying  between  the  cochlea  in  front 
and  the  semicircular  canal  behind,  the  tympanum  being  external.  Its 
outer  or  tympanic  wall  presents  the  fenestra  ovalis. 

Its  inner  wall  has  in  front  a  depression,  t\\Q  fovea  hemispherical  pierced 
by  several  minute  holes  for  the  auditory  filaments,  and,  behind  this,  a 
ridge,  the  aista  vestibuli.  Behind  this  ridge  is  the  opening  of  the  aque- 
ductus  vestibuli.     In  the  roof  is  a  depression,  i\iQ  fovea  hemi-eUiptica. 

Behind,  the  vestibule  presents  five  foramina  leading  into  the  semicir- 
cular canals,  and  in  front  a  larger  foramen  leading  into  the  scala  vestib- 
uli of  the  cochlea. 

The  semicircular  canals  are  three  bony  tubes  of  unequal  length 
lying  above  and  behind  the  vestibule,  each  forming  about  two-thirds  of  a 
circle.  Their  general  diameter  is  ^V  inch,  but  at  one  end  is  a  dilatation, 
the  ampulla,  xV  inch  in  diameter.  They  empty  into  the  vestibule  by  five 
apertures,  in  one  of  which  two  tubes  join. 

The  supanor  is  vertical  and  is  set  transversely,  forming  an  eminence 
seen  on  the  upper  surface  of  the  petrous  bone.  The  ampulla  of  this 
tube  opens  into  the  upper  part  of  the  vestibule,  the  other  end  opening  by 
a  foramen  into  the  back  part,  in  common  with  the  posterior  canal. 

The  posterior  is  also  vertical,  but  is  set  antero-posteriorly  and  is  longer 
than  the  others,  its  ampulla  being  at  the  postero-inierior  part  of  the  vesti- 
bule, the  other  extremity  joining  with  the  preceding  canal,  as  described. 

The  external  is  horizontal  and  the  shortest,  its  ampulla  being  at  the 
outer  part,  above  the  fenestra  ovalis,  and  the  other  end  at  the  upper  and 
back  part  of  the  vestibule. 

The  cochlea  resembles  a  snail-shell.  Its  apex  looks  forward  and  out- 
ward, and  its  base  toward  the  internal  auditory  meatus.  Within  is  a 
centre-piece,  the  modiolus  or  columella,  around  which  the  canal  runs 
spirally  for  two  and  a  half  turns. 

Within  the  canal,  and  attached  to  the  modiolus,  is  the  lamina  spiralis. 
This  plate  of  bone  partially  divides  the  spiral  canal  into  two  compart-, 
ments  or  scalae,  the  division  being  completed  by  a  membrane  (see  below) 
which  reaches  the  outer  wall  of  the  cochlea.  The  upper  scala  is  known 
as  the  scala  vestibuli ;  the  lower  is  the  scala  tympani. 

The  modiolus  or  columella,  the  centre-piece  of  the  cochlea,  runs  from 
base  to  apex.     It  is  conical  in  form,  the  base  corresponding  to  that  of 
the  cochlea,  and  is  pierced  by  foramina  for  the  cochlear  branches  of  th^ 
20— A. 


306  ORGANS   OF   SPECIAL  SENSE. 

auditory  nerve  and  for  the  vessels  which  pass  to  the  lamina  and  spiral 
canal.  One  of  these,  larger  than  the  rest,  is  the  opening  of  the  canalis 
modioli  centralis.  Diminishing  gradually  in  size,  the  modiolus  termi- 
nates above  in  a  bony  process,  the  mfundihulum^  which  blends  with  the 
cupola  or  last  half  turn  of  the  spiral  canal.  Here  the  two  scalae  commu- 
nicate by  a  small  opening,  the  helicotrema.  Around  the  modiolus,  along 
the  attachment  of  the  lamina  spiralis,  is  the  spiral  canal  of  the  modio- 
lus, containing  a  gangliated  portion  of  the  cochlear  nerve,  the  ganglion 
spirale. 

The  spiral  canal  is  1 J  inches  long  and  jV  ii^ch  in  diameter  at  its  widest 
part,  which  is  below.  The  scala  vestibuli  communicates  with  the  vesti- 
bule by  the  foramen  above  mentioned,  and  a  part  of  it,  marked  off  by  a 
membrane,  is  called  the  scala  media  {see  below).  The  scala  tympani 
commences  at  the  fenestra  rotunda,  and  close  to  its  commencement  is  the 
opening  of  the  aqueductus  cochlece^  by  which  it  communicates  with  the 
subarachnoid  space,  and  in  which  there  is  transmitted  a  small  vein  to  the 
internal  jugular.  The  spiral  lamina  ends  above  in  a  hook-like  process, 
the  hamulus^  which  partly  bounds  the  helicotrema. 

Describe  the  membranous  labyrinth. 

The  membranous  labyrinth  is  contained  within  the  osseous  labyrinth, 
having  a  similar  form,  though  smaller  and  separated  from  it  by  the  peri- 
lymph. It  contains  the  endolymph  and  receives  the  distribution  of  the 
auditory  nerve.     In  the  vestibule  it  consists  of  the  utricle  and  the  saccule. 

The  utricle  is  in  the  upper  and  back  part,  its  cavity  communicating 
by  five  apertures  with  the  membranous  semicircular  canals.  It  is  in  con- 
tact with  the  fovea  hemi-elliptica.  ^ 

The  saccule  is  in  the  fovea  hemispherica,  and  communicates  with  the 
utricle  by  means  of  a  small  tube  which  passes  into  the  aqueductus  vesti- 
buli, and  there  joins  a  canal  (saccus  endolymphaticus)^  which  canal  is 
prolonged  from  the  utricle  and  ends  in  a  blind  extremity ;  and  with  the 
scala  media  by  means  of  the  canalis  reuniens. 

The  membranous  semicircular  canals  are  similar  in  shape  to,  but  are  only 
from  one-fifth  to  one-third  the  diameter  of,  the  bony  canals ;  the  ampullae, 
however,  are  relatively  large.  Two  small  masses  of  calcium  carbonate 
are  found  in  the  utricle  and  saccule.     They  are  called  the  otoliths. 

In  the  cochlea  the  membranous  labyrinth  is  represented  by  the  scala 
media  and  the  parts  therein,  which  are  formed  as  follows : 

Along  the  edge  of  the  spiral  lamina  the  periosteum  on  its  upper  sur- 
face is  raised  up  like  a  C  to  form  the  limbus  laminae  spiralis.  Thus 
there  is  a  groove  (the  sulcus  spiralis),  the  upper  and  lower  lips  of  this 
sulcus  being  called  respectively  the  labium  vestibulare  and  tympanicum. 
From  the  latter  the  membrana  basilaris  extends  to  the  outer  wall,  along 
the  latter  attachment  forming  the  ligamentum  spirale.  Above  the  lim- 
bus to  the  outer  wall  stretches  another  membrane,  Reissners.  The 
space  below  the  osseous  lamina  and  the  membrana  basilaris  is  the  scala 
tympani ;  ubove  the  membrane  of  Reissner  is  the  scala  vestibuli ;  and  that 


THE   NOSE.  307 

space  bounded  by  the  two  membranes  and  the  outer  wall  of  the  cochlea  is 
known  as  the  scala  media,  or  canal  of  the  cochlea,  which  ends  at  the  apex 
of  the  cochlea  in  a  blind  pointed  extremity,  and  opens  below  into  the 
saccule,  as  described  above.  Between  the  two  membranes  mentioned  a 
third  stretches  across  in  the  scala  media  to  the  outer  wall.  This  is  called 
the  membrane  of  Corti,  or  memhrana  tectoria.  Between  the  membrana 
basilaris  and  the  last-named  membrane  is  a  space  which  contains  the 
organ  of  Corti. 

The  organ  of  Corti  lies  on  the  basilar  membrane.  The  central  part 
is  composed  of  two  rows  of  peculiarly-shaped  cells  called  the  rods  of 
Corti,  outer  and  inner.  These  rods  meet  above  by  their  extremities,  and 
enclose  an  angular  tunnel  between  them  and  the  basilar  membrane,  the 
zona  arcuata.  The  inner  rods  run  close  to  the  labium  tympanicum,  and 
along  their  inner  side  is  a  series  of  epithelioid  cells  continuous  with  the 
cubical  epithelium  of  the  sulcus  spiralis.  These  present  a  row  of  short, 
stiff  hairs,  forming  a  sort  of  brush.  External  to  the  outer  rods  are 
several  rows  of  similar  cells.  These  are  called  the  outer  and  inner  hair- 
cells. 

The  reticular  lamina  is  a  delicate  structure  composed  of  small  seg- 
ments called  phalanges  arranged  side  by  side  and  separated  by  holes, 
through  which  the  hairs  of  the  outer  hair-cells  project.  The  whole 
organ  thus  described  is  covered  by  the  membrane  of  Corti  (membrana 
tectoria). 

Give  the  arterial  and  nervous  supply. 

The  arteries  of  the  internal  ear  are  the  auditory  branch  of  the  basilar, 
the  stylo-mastoid  branch  of  the  posterior  auricular,  and  branches  occa- 
sionally from  the  occipital.  The  first  named  divides  into  a  cochlear  and 
a  vestibular  branch. 

The  auditory  nerve  divides  at  the  bottom  of  the  internal  auditory 
meatus  into  a  superior  and  an  iiifeinor  branch.  The  former  divides  into 
branches,  which  are  distributed  to  the  utricle  and  to  the  ampullae  of  the 
superior  and  external  semicircular  canals ;  the  latter  sends  branches  to 
the  saccule,  to  the  ampulla  of  the  posterior  canal,  and  to  the  cochlea. 

The  cochlear  branch  sends  its  filaments  through  the  canals  of  the 
modiolus,  and  these  form  the  ganglion  spirale.  This  ganglion  sends 
other  filaments  to  the  sulcus  spirale  and  organ  of  Corti. 

THE  NOSE. 
Describe  the  nose. 

The  nose  is  the  organ  of  smell,  and  consists  of  an  external  part,  the 
nose,  and  an  internal,  the  nasal  fossae. 

The  nose  is  triangular,  and  is  formed  by  the  nasal  bones  and  nasal  pro- 
cesses of  the  superior  maxillary  bones,  and  of  five  cartilages — viz.  the  two 
upper  and  the  two  lower  lateral  cartilages,  and  the  cartilage  of  the  sep- 
tum. ^  The  two  openings,  the  anterior  nares,  are  directed  downward,  and 
just  inside  of  them  are  some  short,  stiff  hairs,  the  yibrissae.     The  bones 


308  ORGANS  OF  SPECIAL  SENSE. 

and  cartilages  are  covered  by  skin  on  the  outer  side  and  by  mucous  mem- 
brane on  the  inner.  Between  the  anterior  nares  is  a  fold  of  skin,  the 
columna  7iasi,  which  continues  the  septum.  The  two  lateral  parts  join 
in  front  to  form  the  dorsum,  and  this  ends  below  in  the  rounded  lobe  of 
the  nose. 

The  upper  lateral  cartilages  lie  one  on  each  side,  below  the  nasal  bones, 
and  are  triangular  in  form.  The  anterior  margin  joins  its  fellow  above 
and  the  edge  of  the  cartilage  of  the  septum  below.  The  inferior  edge 
joins  the  lower  lateral  cartilage  by  means  of  fibrous  tissue,  and  the  pos- 
terior edge  the*  nasal  and  superior  maxillary  bones. 

The  lower  lateral  cartilages  are  thin,  and  are  curved  so  as  to  form  the 
front  and  both  walls  of  the  nostrils.  Behind  it  is  attached  to  the  supe- 
rior maxilla,  above  to  the  upper  cartilage.  Between  it  and  the  former 
several  smaller  cartilages  may  be  seen,  it  also  joins  a  small  part  of  the 
cartilage  of  the  septum.  In  front  it  joins  its  fellow  to  form  the  tip  of 
the  nose. 

The  cartilage  of  the  septum  is  quadrilateral,  and  thinner  at  the  centre 
than  at  its  borders.  It  forms  the  anterior  part  of  the  septum,  and  is 
joined  superiorly  to  the  nasal  bones,  and  to  the  upper  and  lower  lateral 
cartilages  by  its  anterior  margin.  Its  posterior  margin  is  attached  to  the 
front  of  the  perpendicular  plate  of  the  ethmoid,  and  its  lower  margin  to 
a  groove  on  the  vomer  and  the  ridge  between  the  superior  maxillae. 

The  arteries  are  the  lateralis  nasi,  artery  of  the  septum  from  the  supe- 
rior coronary,  infraorbital,  and  nasal  branch  of  the  ophthalmic. 

The  veins  end  in  the  facial  and  ophthalmic. 

The  nerves  are  from  the  facial,  infraorbital,  infratrochlear,  and  nasal 
branch  of  the  ophthalmic. 

Describe  the  itasal  fossae. 

For  the  osseous  part,  see  Bones.  These  fossae  open  in  front  by  the  an- 
terior nares,  and  into  the  pharynx  behind  by  the  posterior  nares.  The 
mucous  membrane  is  called  the  pituitary  or  Schneiderian  membrane,  and 
is  attached  directly  to  the  periosteum  or  perichondrium.  It  is  continu- 
ous with  that  of  the  pharynx,  conjunctiva,  tympanum,  and  mastoid  cells, 
antrum  of  Highmore,  and  with  that  of  the  different  canals  which  con- 
nect these  parts. 

The  epithelium  is  squamous  near  the  nostril,  columnar  where  the  olfac- 
tory nerves  are  distributed,  and  columnar  and  ciliated  elsewhere. 

The  nasal  fossae  in  the  recent  state  present  a  different  appearance  from 
that  seen  in  the  skeleton.  They  are  narrowed,  and  their  component 
parts  appear  thicker,  the  turbinated  bones  being  very  prominent.  The 
apertures  of  the  various  foramina  are  narrowed,  or  even  closed,  by  the 
lining  membrane. 

The  arteries  of  the  nasal  fossae  are  the  ethmoidal,  the  small  meningeal, 
spheno-palatine,  and  alveolar. 

The  veins  empty  into  the  ophthalmic  and  facial,  and  through  the  for- 
amen caecum  communicate  with  the  cranial  sinuses. 


THE  TONGUE.  309 

The  nerves  are  the  olfactory  filaments  distributed  to  the  upper  third 
of  the  septum  and  the  surfaces  of  the  superior  and  middle  turbinated 
bone  (these  filaments  do  not  reach  the  superior  or  middle  meatus),  the 
nasal  branch  of  the  ophthalmic,  the  anterior  dental  of  the  superior  max- 
illary, and  the  Vidian,  naso-palatine,  and  anterior  palatine. 

THE  TONGUE. 
Describe  the  tongue. 

The  tongue  is  composed  of  muscular  substance  covered  by  mucous 
membrane.  Behind  it  is  attached  to  the  hyoid  bone,  and  below  by 
means  of  the  genioglossus  to  the  lower  jaw.  The  mucous  membrane  is 
continuous  with  that  of  the  gums,  and  forms  on  the  middle  line  of  the 
under  surface  a  fold,  the  frceniim  Jinguce.  Along  the  middle  line  of  the 
dorsum  is  a  depression,  the  rapM^  which  ends  in  the  foramen  ccecum,  I 
inch  frona  the  base.  At  its  base  three  folds  of  mucous  membrane,  the 
glosso-epiglottic  Hgaments,  connect  it  with  the  epiglottis. 

The  anterior  two-thirds  of  the  dorsum  is  covered  with  papillce,  as  well 
as  the  tip  and  borders.  These  are  of  three  kinds,  circumvallate,  fungi- 
form, and  conical,  and  are  covered  by  minute  secondary  papillae. 

The  circumvallate  (papillae  maximae),  eight  to  ten  in  number,  run  from 
the  foramen  caecum  in  two  lines  forward  and  outward,  making  a  V. 
Each  papilla  lies  in  a  depression  which  is  surrounded,  in  turn,  by  an 
elevated  ring. 

The  fungiform  (mediae)  are  smaller  and  more  numerous.  They  occupy 
the  middle  and  front  part  of  the  dorsum,  and  occur  at  the  apex  and  near 
the  borders. 

The  conical  papillce  (minimae)  are  the  smallest  and  most  numerous, 
and  are  found  all  over  the  dorsum.  They  run  in  lines  which  diverge 
from  the  raphe  obhquely  behind,  nearly  transversely  in  front. 

The  secondary  papillae  send  ofi"  fine  processes,  which  give  the  appear- 
ance called  filiform. 

The  glands  of  the  mucous  membrane  are  of  two  kinds,  mucous  and 
serous  glands. 

A  quantity  of  lymphoid  tissue  is  found  between  the  epiglottis  and 
papillae  maximae,  collected  into  masses,  the  follicles.  The  epithelium  is 
stratified. 

The  tongue  is  divided  by  2i  fibrous  septum  into  two  symmetrical  lateral 
halves :  this  septum  is  connected  to  the  hyoid  bone  by  the  so-called  hypo- 
glossal membrane,  which  receives  some  of  the  fibres  of  the  genio-hyo- 
glossus  muscle. 

The  tongue  has  extrinsic  and  intrinsic  muscular  fibres.  The  former 
include  the  hyoglossus,  genioglossus,  styloglossus,  palatoglossus,  and  part 
of  the  superior  constrictor.  The  intrinsic  muscles  are  the  various  parts 
of  the  lingualis.  These  parts  are  the  superior  and  inferior  longitudinal, 
vertical,  and  transverse. 


310  ORGANS   OF   RESPIRATION. 

The  arteries  are  the  Ungual  and  branches  of  the  ascending  pharyngeal 
and  facial.     The  veins  join  the  internal  jugular. 

The  nerves  are  four  in  number :  the  lingual  branch  of  the  fifth  (gus- 
tatory), to  its  anterior  two-thirds;  the  lingual  branch  of  the  glosso- 
pharyngeal, to  the  base  and  papillas  maximae ;  the  hypoglossal,  to  the 
muscles ;  and  the  chorda  tympani,  to  the  lingualis.  It  also  receives  sym- 
pathetic branches. 

The  glosso-pharyngeal  confers  taste ;  the  gustatory,  common  sensation ; 
and  the  hypoglossal,  motion ;  also  the  facial,  by  means  of  fibres  from  the 
chorda  tympani. 

SPLANCHNOLOGY. 

Organs  of  Respiration. 

THE   LARYNX. 
Give  a  general  description  of  the  larynx. 

The  larynx  is  the  organ  of  voice,  and  is  placed  at  the  upper  and  fore 
part  of  the  neck,  between  the  trachea  and  base  of  the  tongue.  It  has 
on  each  side  of  it  the  great  vessels,  and  behind  it  the  pharynx.  In  front 
are  the  cervical  fascia  mesially  and  the  upper  end  of  the  thyroid  gland, 
and  on  each  side  the  sterno-hyoid  and  thyroid  and  the  thyro-hyoid  mus- 
cles. It  consists  of  various  cartilages  held  together  by  ligaments,  and  is 
lined  internally  by  mucous  membrane. 

What  are  the  cartilages  ? 

The  cartilages  are  nine :  three  pairs,  the  arytenoid,  cornicula  laryngis, 
and  cuneiform ;  and  three  single,  the  thyroid,  cricoid,  and  epiglottis. 

Describe  the  thyroid  cartilage. 

It  is  the  largest,  and  consists  of  two  lateral  parts  or  alae  uniting  in 
front  to  form  the  projection  of  the  pomum  Adami.  This  is  subcutaneous, 
more  distinct  above  and  in  the  male.  ^  Each  ala  is  quadrilateral,  and  pre- 
sents externally  a  tubercle  from  which  a  ridge  descends  obliquely  for- 
ward. This  ridge  gives  attachment  to  the  sterno-thyroid  and  thyro-hyoid, 
and  the  surface  behind  it  to  the  inferior  constrictor  muscle.  Internally 
it  is  smooth,  and  in  the  angle  the  epiglottis,  true  and  false  vocal  cords, 
and  the  thyro- arytenoid  and  thyro-epiglottic  muscles  are  attached.  The 
upper  border  is  concavo-convex,  and  in  front  is  notched  ov^r  the  pomum 
Adami,  giving  attachment  throughout  to  the  thyro-hyoid  membrane. 
The  lower  border  is  joined  to  the  cricoid  cartilage  by  the  crico-thyroid 
membrane.  The  posterior  borders  end  in  the  upper  and  lower  cormut  : 
to  the  upper  are  attached  the  lateral  thyro-hyoid  ligaments,  and  the 
lower,  which  are  shorter  and  thicker,  present  internally  a  facet  for 
articulation  with  the  cricoid  cartilage.  The  stylo-  and  palato-pharyngei 
are  attached  also  to  the  posterior  border. 


^HE   LARYNX.  3ll 

Describe  the  cricoid  cartilage. 

It  resembles  a  signet  ring,  is  narrow  in  front,  and  gives  attachment  to 
the  crico-thyroid  muscle,  and  behind  it  to  some  of  the  fibres  of  the 
inferior  constrictor.  It  is  broad  behind,  with  a  median  ridge  for  the 
oesophagus,  separating  two  hollows  for  the  crico-arytenoideus  posticus, 
and  presents  at  about  the  middle  of  the  lateral  surface  a  prominence 
on  each  side  which  articulates  with  the  corresponding  inferior  cornu  of 
the  thyroid  cartilage.  The  lower  border  is  joined  to  the  upper  ring  of 
the  trachea ;  the  upper  gives  attachment  in  front  and  laterally  to  the 
crico-thyroid  membrane  and  the  lateral  crico-arytenoideus  muscle.  Be- 
hind, at  each  end  of  its  upper  border,  is  an  oval  surface  for  the  corre- 
sponding arytenoid  cartilage,  with  a  notch  between. 

Describe  the  arytenoid  cartilages. 

They  are  pyramidal  in  form,  and  rest  by  their  bases  on  the  highest  part 
of  the  upper  border  of  the  cricoid  cartilage  behind,  their  curved  apices 
approximating.  To  the  posterior  surface  is  attached  the  arytenoideus ; 
to  the  anterior,  the  thyro-arytenoideus  and  the  false  vocal  cord ;  and  the 
internal  is  covered  by  mucous  membrane.  The  apex  is  curved  backward 
and  inward,  and  surmounted  by  the  corniculum  laryngis.  The  base  pre- 
sents a  concave  surface  to  articulate  with  the  cricoid  cartilage,  and  to  its 
external  angle  [muscular  process)  are  attached  the  lateral  and  posterior 
crico-arytenoidei,  and  to  the  anterior  angle  [vocal  process)  the  true  vocal 
cord. 

The  cormcula  laryngis  (cartilages  of  Santorini)  are  two  small,  conical, 
yellowish  bodies  which  prolong  the  apices  of  the  arytenoid  cartilages 
backward  and  inward. 

The  cuneiform  cartilages  (Wrisberg's)  are  two  small,  yellow,  elongated 
bodies  lying  one  in  each  fold  of  the  mucous  membrane  which  stretches 
between  the  arytenoid  cartilage  and  the  epiglottis. 

The  epiglottis  is  a  tibro-cartilaginous  lamella,  shaped  like  a  leaf,  lying 
behind  the  tongue  and  in  front  of  the  upper  orifice  of  the  larynx.  Above 
it  is  broad,  below  narrow  and  prolonged  to  the  notch  above  the  pomum 
Adami  by  the  thyro-epiglottic  Ugament,  or,  rather,  to  the  angular  inter- 
val just  below  the  notch,  and  is  attached  to  the  body  of  the  hyoid  bone 
by  the  hyo-epi glottic  ligament.  Laterally  are  attached  the  aryteno-epi- 
glottic  folds.  The  anterior  surface  is  connected  with  the  tongue  by  the 
lateral  and  median  glosso- epiglottic  folds.  The  posterior  surface  is  con- 
cave transversely,  convex  longitudinally. 

Describe  the  ligaments  of  the  larynx. 

These  are  extrinsic  and  intrinsic.  The  former  connect  it  to  the  hyoid 
bone ;  the  latter  connect  its  parts  together. 

The  extrinsic  are  the  middle  thyro-hyoid  ligament,  the  two  lateral 
thyro-hyoid  ligaments,  and  the  hyo-epiglottic  ligament. 

The  middle  thyro-hyoid  ligament  is  a  fibro-elastic  structure  attached 
to  the  entire  border  of  the  notch  of  the  thyroid  cartilage  and  to  the 


312  ORGANS   OF   RESPIRATION.. 

upper  border  of  the  posterior  surface  of  the  body  of  the  hyoid  bone. 
The  lateral  thyro-hyoid  ligaments  run  between  the  upper  cornua  of  the 
thjToid  and  the  greater  cornua  of  the  hyoid  bone.  They  sometimes 
enclose  the  cartilago  triticea,  a  small  cartilaginous  nodule  occasionally 
ossified.  The  hyo-epiglottic  ligament  runs  from  the  front  of  the  epiglot- 
tis near  its  apex  to  the  upper  border  of  the  body  of  the  hyoid  bone. 

Describe  the  intrinsic  ligaments. 

The  ligaments  connecting  the  thyroid  and  cricoid  cartilages  are  the 
crico-thyroid  ligament,  the  capsijar  ligaments,  and  the  synovial  mem- 
branes. The  crico-thyroid  ligament  is  of  yellow  elastic  tissue,  trian- 
gular, and  consists  of  a  mesial  thicker  portion  connecting  the  adjacent 
borders  of  the  two  cartilages,  and  two  lateral  portions  running  from  tlie 
upper  border  of  the  cricoid  to  be  continuous  with  the  inferior  thyro-ary- 
tenoid  ligaments  {true  vocal  cords).  In  front  this  ligament  is  partly 
covered  by  the  crico-thyroid  muscles  on  each  side,  and  in  the  subcuta- 
neous interval  there  is  a  sort  of  plexus  from  the  junction  of  the  two 
crico-thyroid  arteries.  The  lower  cornua  of  the  thyroid  are  connected 
with  the  sides  of  the  cricoid  by  two  ligamentous  capsules  each  lined  by 
a  synovial  membrane. 

The  cricoid  and  arytenoid  cartilages  are  connected  by  loose  capsular 
ligaments  lined  by  synovial  membranes,  and  by  a  posterior  crico-aryte- 
noid  ligament  running  from  the  cricoid  to  the  inner  and  back  part  of  the 
base  01  the  arytenoid. 

The  ligaments  of  the  epiglottis  are  the  hyo-epiglottic,  the  three  glosso- 
epiglottic  ligaments  (mucous  membrane),  and  the  thyro-epiglottic.  The 
latter  is  a  long  and  slender  cord  between  the  apex  of  the  epiglottis  and 
the  angle  of  the  thyroid  just  below  the  notch. 

Describe  the  interior  of  the  larynx. 

The  cavity  of  the  larynx  is  divided  into  an  upper  and  a  lower  part  by 
the  rima  glottidis.  The  upper  opens  into  the  pharynx  by  the  upper 
aperture  of  the  larynx,  between  which  and  the  rima  glottidis  are  the 
ventricles  and  their  saccules  and  the  false  vocal  cords.  The  lower  aper- 
ture is  continuous  with  the  trachea. 

The  superior  aperture  is  cordiform  in  shape,  widest  in  front  and  nar- 
row behind.  In  front  it  is  bounded  by  the  epiglottis,  behind  by  the 
arytenoid  cartilages  (together  with  the  fold  of  mucous  membrane  between 
them)  and  cornicula,  and  laterally  by  the  aryteno-epiglottic  folds. 

The  rima  glottidis  is  the  space  between  the  true  vocal  cords  and  the 
bases  of  the  arytenoid  cartilages.  It  is  somewhat  less  than  1  inch  long, 
and,  according  to  its  degree  of  dilatation,  from  J  to  J  an  inch  wide,  in 
easy  respiration  its  form  is  triangular  with  the  base  posterior,  and  when 
fully  dilated  it  is  lozenge-shaped. 

What  are  the  superior  or  false  vocal  cords  ? 
They  are  two  mucous  folds,  each  enclosing  the  corresponding  superior 


THE   LARYNX.  313 

thyro-arytenoid  ligament.     This  latter  is  a  thin  band  running  between  the 
angle  of  the  thyroid  and  the  anterior  surface  of  the  arytenoid  cartilage. 

What  are  the  inferior  or  true  vocal  cords  ? 

They  are  two  strong  bands,  the  inferior  thyro-arytenoid  ligaments,  cov- 
ered by  mucous  menabrane  and  attached  to  the  depression  between  the 
aise  of  the  thyroid  cartilage  in  front  and  the  anterior  angle  of  the  base 
(vocal  process)  of  the  arytenoid  cartilages  behind.  Below,  each  is  contin- 
uous with  the  lateral  part  of  the  crico-thyroid  ligament  or  membrane. 
Part  of  the  thyro-arytenoidei  is  external  and  parallel  to  them. 

Describe  the  ventricles  of  the  larynx. 

The  ventricles  of  the  larynx  lie  one  on  each  side,  between  the  upper 
and  lower  vocal  cords,  bounded  externally  by  the  thyro-arytenoidei.  At 
the  front  a  narrow  opening  leads  into  a  blind  pouch,  the  laryngeal  saccule. 

What  is  the  saccule  ? 

The  sacculus  laryngis  is  a  space  on  each  side,  between  the  false  vocal 
cord  and  the  inner  surface  of  the  thyroid  cartilage,  reaching  upward  as 
high  as  the  upper  border  of  that  cartilage,  and  its  mucous  membrane 
presents  the  orifices  of  sixty  or  seventy  glands.  This  space  has  a  fibrous 
capsule.  Its  laryngeal  surface  is  covered  by  the  inferior  aryteno-epiglot- 
tic  muscle,  or  compressor  sacculi  laryngis,  and  its  external  surface  by  the 
thyro-arytenoideus  and  thyro-epiglottic  muscles. 

Name  and  describe  the  intrinsic  muscles  of  the  larynx. 

They  are  the  following : 

(1 )  The  crico-thyroid  arises  from  the  front  part  and  sides  of  the  cricoid 
cartilage,  and  is  inserted  into  the  lower  border  of  the  thyroid  cartilage 
and  the  front  of  its  lower  cornu.  Between  the  two  muscles  is  the  crico- 
thyroid membrane.  The  action  of  the  two  muscles  is  to  approximate 
the  cricoid  to  the  thyroid  and  thus  tense  the  vocal  cords.  The  nerve- 
supply  is  from  the  superior  laryngeal. 

(2)  The  thyro-arytenoid  is  divided  into  two  parts,  outer  and  inner.  It 
arises  in  front  from  the  angle  of  the  thyroid  at  its  lower  part,  and  its 
inner  part  is  inserted  into  the  vocal  process  and  outer  surface  of  the 
arytenoid  cartilage ;  its  outer  part,  into  the  outer  border  and  muscular 
process  of  the  same  cartilage,  above  the  internal  part.  The  internal 
part  is  adherent  and  parallel  to  the  true  vocal  cord  ;  the  outer  is  external 
to  the  sacculus  laryngis.  Their  action  is  to  advance  the  arytenoid  carti- 
lages and  thus  relax  the  vocal  cords.  The  nerve  comes  from  the  inferior 
laryngeal. 

(3)  The  thyro-epiglottic  muscle  arises  from  the  inner  surface  of  the 
thyroid  cartilage,  close  to  the  angle,  and  is  inserted  into  the  sacculus  laryn- 
gis, epiglottis,  and  aryteno-epiglottic  fold.  It  is  really  a  part  of  the 
preceding  muscle.  ^  Its  action  is  to  depress  the  epiglottis  and  compress 
the  sacculus  laryngis.     Its  nerve  is  from  the  inferior  laryngeal. 

(4)  The  superior  aryteno-epiglottic  muscle  arises  from  the  apex  of  the 


314  ORGANS   OF   RESPIRATION. 

arytenoid,  and  is  enclosed  by  the  aryteno-epiglottic  mucous  folds  bearing 
the  same  name.  Additional  fibres  from  each  muscle  decussate.  These 
fibres  extend  from  the  apex  of  one  cartilage  to  the  muscular  process  of 
the  other,  and  lie  behind  and  on  the  arytenoideus.  Its  action  is  to  dimin- 
ish the  size  of  the  superior  aperture  of  the  larynx  during  deglutition. 
Its  nerve  is  from  the  inferior  laryngeal. 

(5)  The  inferior  aryteno-epiglottic  muscle  arises  from  the  arytenoid 
cartilage,  just  above  the  false  cord,  and  is  inserted  into  the  upper  and 
inner  part  of  the  epiglottis.  Its  other  name,  compressor  sacculi  laryngis, 
indicates  its  action.  It  is  really  a  part  of  the  thyro-arytenoid  muscle. 
Its  nerve  is  from  the  inferior  laryngeal. 

(6)  The  crico-arytenoideus  posticus  arises  from  the  back  of  the  cricoid 
cartilage,  and  is  inserted  into  the  muscular  process  of  the  arytenoid. 
Its  action  is  to  rotate  the  corresponding  arytenoid  oijtward  and  thus  to 
widen  the  glottis.     The  nerve  is  from  the  inferior  laryngeal. 

(7)  The  crico-arytenoideus  lateralis  arises  from  the  upper  border  of  the 
cricoid  cartilage,  and  is  inserted  into  the  muscular  process  of  the  arytenoid 
cartilage.  Its  action  is  to  rotate  the  corresponding  cartilage  inward,  thus 
narrowing  the  glottis.     The  nerve  is  from  the  inferior  laryngeal. 

(8)  The  ai^tenoideus  is  attached  to  the  posterior  surface  of  each  aryte- 
noid cartilage.  Its  fibres  run  transversely.  Its  action  is  to  close  the 
back  part  of  the  glottis  by  means  of  the  approximation  of  the  arytenoid 
cartilages.  Its  nerve-supply  is  from  both  superior  and  inferior  laryngeal 
nerves. 

THE  TRACHEA. 

Describe  the  trachea. 

The  trachea  is  a  membrano-cartilaginous  tube,  flattened  behind,  con- 
tinuous above  with  the  larynx,  and  below  dividing  into  the  two  bronchi. 
Its  upper  limit  is  at  the  sixth  cervical,  its  lower  at  the  disk  between  the 
fourth  and  fifth  dorsal  vertebrae,  and  it  measures  about  4i  inches  in 
length;  transversely,  f  to  1  inch. 

What  are  its  relations? 

In  front :  in  the  neck^  the  isthmus  of  the  thyroid,  the  sterno-hyoid 
and  thyroid  and  the  cervical  fascia  between  them,  the  arteria  thyroidea 
ima,  the  inferior  thyroid  veins,  and  the  communicating  branches  between 
the  anterior  jugulars ;  in  the  thorax^  the  manubrium  sterni,  thymic  re- 
mains, the  left  innominate  vein,  arch  of  the  aorta,  innominate  and 
left  carotid  vessels,  and  the  deep  cardiac  plexus.  Behind  is  the  oesoph- 
agus. Laterally :  in  the  neck,  the  common  carotids,  the  lateral  lobes 
of  the  thyroid,  the  inferior  thyroid  arteries,  and  the  recurrent  nerves ; 
in  the  chesty  the  pleura  of  each  side  and  the  vagus. 

Describe  the  bronchi. 

The  bronchi  enter  the  root  of  the  corresponding  lung.  The  right  is 
the  shorter,  wider,  and  more  horizontal,  and  enters  the  lung  opposite 


THE   THYROID   AND   THYMUS   GLANDS,    ETC.  315 

the  fifth  dorsal  vertebra,  the  larger  azygos  vein  arching  over  it  from  be- 
hind, the  right  pulmonary  artery  being  below  and  then  in  front  of  it.  The 
left  iDronehus  is  about  2  inches  long,  and  enters  the  lung  opposite  the 
sixth  dorsal  vertebra.  It  passes  under  the  arch  of  the  aorta  and  crosses 
in  front  of  the  oesophagus,  thoracic  duct,  and  descending  aorta.  The 
left  pulmonary  artery  lies  at  first  above,  then  in  front  of  it. 

What  is  the  structure  of  the  trachea  ? 

The  trachea  consists  of  sixteen  to  twenty  incomplete  cartilaginous 
rings  connected  by  a  fibrous  membrane.  Their  free  ends,  which  are 
directed  posteriorly,  are  united  similarly  and  by  plain  muscular  tissue. 

THE  THYROID  AND  THYMUS  GLANDS. 
Describe  the  thyroid  gland. 

The  thyroid  gland  is  a  highly  vascular  body  situated  at  the  upper  part 
of  the  trachea,  and  consists  of  two  lateral  lobes  connected  by  the  isthmus. 
The  lateral  lobes  are  placed  one  on  each  side  of  the  trachea. 

In  front  it  is  convex  and  covered  by  the  sterno-hyoid  and  thyroid  and 
omo-hyoid  muscles ;  laterally,  also  convex,  it  touches  the  common  carotid 
sheath ;  behind  it  is  concave  and  rests  on  the  larynx  and  trachea. 

The  weight  of  this  body  is  from  1  to  2  ounces,  its  color  brownish-red, 
and  each  lobe  is  2  inches  long  by  1}  inches  wide.  There  is  sometimes  a 
third  and  accessory  smaller  lobe,  called  the  pyramid. 

Describe  the  thymus  gland. 

The  thymus  is  a  temporary  organ,  attaining  its  greatest  size  at  the  end 
of  the  second  year,  and  gradually  dwindling  thereafter  to  a  mere  trace. 
At  its  full  growth  it  lies  in  the  neck  and  superior  mediastinum,  and  con- 
sists of  two  lobes  extending  behind  the  sternum  from  the  level  of  the 
fourth  cartilage  below  to  the  thyroid  gland  above. 

In  front  are  the  sternum,  sterno-,  hyoid  and  thyroid ;  behind  are  the 
pericardium,  the  great  vessels,  and  the  trachea.  For  the  structure  of 
these  bodies  see  Histology  of  this  series. 

PLEUBiE  AND  MEDIASTINUM. 
Describe  the  pleurae. 

The  pleurae  are  two  separate  serous  sacs  which  invest  each  lung  to  its 
root  and  are  reflected  on  to  the  thoracic  walls  and  pericardium.  The  first 
portion  is  the  visceral  layer,  or  pleura  pulmonalis;  the  second  is  the 
parietal  layer,  or  pleura  costalis. 

The  two  pleurae  are  distinct  from  each  other,  and  do  not  meet  in  the 
median  line  except  behind  the  second  piece  of  the  sternum.  At  the 
root  of  the  lung  the  visceral  and  parietal  layer  of  the  same  side  are  con- 
tinuous, and  at  the  lower  part  of  the  root  a  fold,  the  ligamentum  latum 
pulmonis,  runs  down  to  the  diaphragm. 


316  ORGANS   OF   RESPIRATION. 

What  is  the  mediastinum,  and  how  is  it  subdivided? 

The  mediastinum  is  the  space  between  tlie  two  pleural  sacs,  and  ex- 
tends antero-posteriorly  from  the  sternum  to. the  spine ;  it  is  divided  into — 
a  superior  mediastinum,  above  the  upper  level  of  the  pericardium ;  the 
anterior^  in  front  of  the  pericardium ;  the  middle^  containing  the  peri- 
cardium ;  and  the  posterior  mediastinum,  behind  the  pericardium. 

Describe  each  of  these  subdivisions. 

The  sitperior  mediastinum  is  bounded  by  the  manubrium  sterni  in 
front,  the  upper  four  dorsal  vertebrae  behind,  and  below  by  a  plane  pass- 
ing from  the  lower  border  of  the  manubrium  to  the  lower  part  of  the 
fourth  dorsal  vertebra.  It  contains  the  lower  part  of  the  sterno-hyoid 
and  thyroid  and  longus  colli  muscles,  the  transverse  aorta,  innominate, 
left  carotid,  and  subclavian  arteries,  the  superior  cava  (upper  part),  the 
two  innominate  and  the  left  superior  intercostal  veins,  the  vagus,  car- 
diac, phrenic,  and  left  recurrent  nerves,  trachea,  oesophagus,  thoracic 
duct,  thymic  remains,  and  l3^mphatics. 

The  anterior  mediastinum  is  bounded  by  the  sternum  and  the  peri- 
cardium before  and  behind,  by  the  pleurae  laterally.  It  runs  toward  the 
left,  is  broader  below  than  above,  and  contains  the  origins  of  the  tri- 
angularis sterni,  the  left  internal  mammary  vessels,  some  areolar  tissue 
containing  lymphatics,  and  the  anterior  mediastinal  glands. 

The  middle  mediastinum  contains  the  heart  and  pericardium,  ascend- 
ing aorta,  superior  cava  (lower  part),  bifurcation  of  trachea,  pulmonary 
vessels,  the  phrenic  nerves,  and  the  arch  of  the  vena  azj^gos. 

The  posterior  m^ediastinum  is  behind  the  pericardium  and  roots  of  the 
lungs,  and  in  front  of  the  lower  eight  dorsal  vertebrae,  the  pleurae  bound- 
ing it  on  each  side.  It  contains  the  descending  part  of  the  arch,  the 
thoracic  aorta,  the  azygos  veins,  and  vagi,  oesophagus,  thoracic  duct, 
and  some  lymphatic  glands. 

THE  LUNGS. 
Describe  the  lungs. 

The  lungs  are  placed  one  in  each  side  of  the  chest,  in  contact  with  its 
inner  surface,  and  present  each  for  examination  an  apex,  a  base,  two 
borders,  and  two  surfaces. 

The  apex  extends  1  to  1 J  inches  above  the  first  rib,  and  is  marked  by 
a  groove  for  the  subclavian  artery.  The  base  is  concave  and  rests  on  the 
diaphragm,  its  thin  margin  fitting  into  the  space  between  the  ribs  and 
diaphragm.  The  outer  surface  is  smooth  and  convex  ;  the  inner  surface 
is  concave  and  adapted  to  the  pericardium,  and  behind  is  marked  by  a 
fissure,  the  hilum  pulmonis,  for  the  root  of  the  lung.  The  posterior 
border  is  rounded,  fits  into  the  concavity  on  either  side  of  the  spine,  and 
is  the  longest  part  of  the  lung ;  the  anterior  border  is  sharp  and  over- 
laps the  pericardium.    That  of  the  right  lung  runs  mesially  as  far  as  the 


PLATE  XXVII. 

Fig.  1.— To  face  page  315. 


TRIANGULARIS    STERNI. 

Internal  Mammary  Vessels. 


t  Phrenic  Xer 


Pleura  Pulmonalis. 
Pleura  Costalis. 


Mediastinum  I  ^y^^P^^^^^^^  ^^^'"^' 
meaiastinum  |  Thoracic  Duct. 


.^     Vena  Azygos  Major )  p^.terior. 
Pneumoqastric  Nerves ) 


A  Transverse  Section  of  the  Thorax,  showing  the  relative  position  of  the 
viscera  and  the  reflections  of  the  pleurae. 


PLATE  XXVIII. 

Fig.  1.— To  face  page  317. 


Front  View  of  the  Heart  and  Lungs. 


THE   LUNGS.  317 

sixth  cartilage ;  the  left  only  to  the  fourth  cartilage,  below  which  is  a 
notch  exposing  the  pericardium. 

What  are  the  fissures  of  the  lungs  ? 

Each  lung  is  divided  by  a  deep  fissure,  which  runs  from  the  upper 
part  of  the  posterior  border,  3  inches  below  the  top,  to  the  lower  part 
of  the  anterior  border,  into  two  lobes.  The  upper  lobe  of  the  right 
lung  is  subdivided  by  a  short  fissure  running  from  the  middle  of  the 
preceding  fissure,  forward  and  upward  to  the  anterior  margin,  the  part 
below  being  the  middle  lobe. 

The  right  lung  is  the  larger,  although  the  shorter,  and  it  is  also  the 
heavier. 

Describe  the  root  of  the  lung. 

The  root  of  each  lung  is  a  little  above  and  behind  the  centre,  and 
includes  the  bronchus,  pulmonary  and  bronchial  vessels,  pulmonary 
plexus,  areolar  tissue,  lymphatics,  and  bronchial  glands,  these  all  being 
enclosed  by  a  fold  of  the  pleura.  The  root  of  the  right  lung  is  placed 
behind  the  superior  cava  and  ascending  arch  and  below  the  azygos 
major  vein,  and  the  left  under  the  arch  of  the  aorta  and  in  front  of  the 
descending  part  of  the  arch.  In  front  of  each  are  the  phrenic  nerve 
and  anterior  pulmonary  plexus,  and  behind  each  are  the  posterior  plexus 
and  the  vagus. 

The  pulmonary  vein,  artery,  and  the  bronchus  and  bronchial  vessels 
lie  in  the  order  named  from  before  backward ;  from  above  downward  on 
the  right  side  they  run,  bronchus,  artery,  vein ;  on  the  left  side,  artery, 
bronchus,  vein. 

What  are  the  weight  and  general  structure  of  the  lungs  ? 

The  right  lung  weighs  22  ounces,  the  left  20  ounces,  and  their  color, 
at  birth  a  pink,  darkens  with  age. 

The  lungs  have  an  outer  serous  coat,  under  this  a  subserous  coat, 
and  under  this  latter  the  pulmonary  parenchyma.  The  serous  coat  is 
the  pleura ;  the  subserous  areolar  tissue  under  it  enters  in  between  the 
lobules. 

The  lung  is  composed  of  lobules  which  are  largest  toward  the  periph- 
ery, and  each  is  made  up  of  a  lobular  bronchial  tube  With,  its  ramifica- 
tions, and  includes  branches  of  the  pulmonary  and  bronchial  vessels, 
nerves,  and  lymphatics,  all  connected  together  by  areolar  fibrous  tissue. 

What  is  the  arrangement  of  the  bronchi  within  the  lung  ? 

Both  bronchi ^  enter  the  lungs,  the  right  giving  off"  a  branch  to  the 
upper  lobe,  dividing  dichotomously,  the  cartilaginous  rings  becoming 
shorter  until  they  are  mere  plates  without  regular  distribution.  The 
muscular  coat  is  continuous  around  the  tubes,  and  the  mucous  mem- 
brane throughout  is  columnar  and  ciliated.  Each  lobular  bronchial  tube, 
above  mentioned,  on  entering  a  lobule  becomes  beset  with  air-cells  or 


318  THE   ORGANS   OF   DIGESTION. 

alveoli  Finally,  it  ends  as  the  alveolar  passage^  from  which  are  given 
oiF  blind  ramifications  or  infundibula.  These  are  also  beset  with  air- 
cells. 

What  can  you  say  of  the  blood-vessels  of  the  lungs  ? 

The  pulmonary  artery  divides,  and  its  divisions  accompany  those  of  the 
bronchi.  Finally  a  capillary  plexus  is  formed  on  the  walls  of  the  air- 
cells  and  alveolar  passages,  which  lies  just  beneath  the  mucous  mem- 
brane, and  from  this  plexus  the  pulmonary  veins  arise. 

The  bronchial  arteries  nourish  the  lungs,  and  in  like  manner  accom- 
pany the  tubes.  They  supply  also  the  bronchial  glands,  and  end  in  the 
bronchial  veins.  These  veins  do  not  receive  all  the  blood  from  the  cor- 
responding artery,  as  the  pulmonary  veins  return  a  part  of  it.  The  left 
empties  into  the  superior  intercostal ;  the  right,  into  the  azygos  major 
vein. 

THE  ORGANS  OP  DIGESTION. 

THE   MOUTH. 
Describe  the  mouth. 

The  mouth  is  the  upper  part  of  the  alimentary  canal.  It  is  bounded 
by  the  lips,  cheeks,  tongue,  hard  and  soft  palate,  alveolar  processes  of 
both  jaws,  with  their  contained  teeth,  and  opens  behind,  through  the 
isthmus  faucium,  into  the  pharynx.  It  is  lined  by  mucous  membrane 
continuous  in  front  with  the  skin,  behind  with  that  of  the  fauces,  its  epi- 
thelium being  stratified. 

Describe  the  lips  and  cheeks. 

They  are  formed  of  skin  externally  and  of  mucous  membrane  inter- 
nally, enclosing  between  them  muscles,  vessels,  nerves,  areolar  tissue,  fat, 
and  glands.  In  the  cheeks  are  the  buccal  glands,  similar  to  but  smaller 
than  the  labial,  and  opposite  the  second  upper  molar  tooth  is  a  papilla, 
the  summit  of  which  presents  the  orifice  of  the  parotid  duct.  Several 
larger  buccal  glands  open  opposite  the  last  molar  tooth.  They  lie  be- 
tween the  buccinator  and  masseter,  and  are  called  the  molar  glands. 
The  labial  glands  are  about  the  size  of  small  peas,  and  lie  just  beneath 
the  mucous  membrane.  The  inner  surface  of  each  lip  in  the  middle  line 
is  joined  to  the  gum  of  the  corresponding  jaw  by  a  mesial  fold  of  mucous 
membrane,  the  fraenum.     The  upper  is  the  larger. 

Describe  the  gums. 

They  are  formed  of  fibrous  tissue  intimately  joined  to^  the  alveolar 
periosteum,  and  are  covered  by  mucous  membrane  containing  papillae 
close  to  the  teeth. 

THE   TEETH. 
Describe  the  teeth. 
There  are  in  the  human  subject  two  sets  of  teeth,  a  temporary  set,  or 


THE  TEETH.  319 

milk  teeth,  and  a  permanent  set.  The  former  are  twenty  in  number, 
ten  in  each  jaw ;  the  latter,  thirty-two,  sixteen  each  above  and  below. 
Each  tooth  is  made  up  of  three  parts :  the  root,  consisting  of  one  or 
more  fangs,  contained  in  the  alveolus ;  the  crown  or  body,  above  the  gum ; 
and  the  neck,  between  the  two.  The  alveolar  periosteum  is  reflected 
on  to  the  fang  as  far  as  the  neck. 

How  are  the  teeth  divided? 

The  twenty  temporary  teeth  are  divided  into  four  incisors,  two  canines, 
and  four  molars  above  and  below.  The  thirty-two  permanent  teeth  are, 
four  incisors,  two  canines,  four  bicuspids,  and  six  molars  in  each  jaw. 
The  temporary  teeth  are  similar  to  but  smaller  than  the  permanent ;  of 
the  temporary  molars,  the  hinder  one  is  the  largest  of  all,  and  its  place 
is  afterward  taken  by  the  second  permanent  bicuspid. 

Describe  the  permanent  teeth. 

Of  the  permanent  teeth  the  incisors  are  the  eight  central  cutting 
teeth,  four  each  above  and  below,  the  former  being  the  larger.  They 
are  bevelled  at  the  expense  of  the  posterior  surface.  The  canines  {cus- 
pldati)  are  two  in  each  jaw,  being  situated  one  behind  each  lateral  incisor, 
the  upper  and  larger  being  called  the  eye-teeth.  The  bicuspids  [pre- 
molars or  false  molars),  four  in  each  jaw,  lie  two  each  behind  the  canines, 
the  upper  being  the  larger.  The  molars  {true  molars  or  multicuspidati) 
are  the  largest  teeth,  and  number  six  in  each  jaw,  three  each  behind  the 
posterior  bicuspids  above  and  below.  They  present  four  tubercles  on  the 
upper,  five  on  the  lower  crowns,  and  the  root  is  subdivided  into  from  two 
to  five  fangs.  The  first  molar  is  the  largest  and  broadest,  the  second  is 
smaller,  and  the  third  (wisdom  tooth)  the  smallest. 

Give  the  structure  of  a  tooth. 

A  vertical  section  of  a  tooth  shows  it  to  be  hollow,  the  cavity  being 
continuous  with  the  aperture  in  the  fang  and  filled  up  with  the  soft  den- 
tal pulp,  and  is  hence  called  the  pulp-cavity.  The  pulp  is  sensitive, 
highly  vascular,  and  consists  of  connective  tissue  with  cells,  vessels,  and 
nerves.  The  hard  substance  of  each  tooth  consists  of  three  parts :  the 
ivory  or  dentine,  the  enamel,  and  the  crusta  petrosa  or  cement. 

The  dentine  forms  the  chief  mass,  consisting  of  fine  tubes,  the  den- 
tal tubuli,  imbedded  in  a  homogeneous  matrix,  the  intertubular  tissue. 
These  tubuli  open  into  the  pulp-cavity. 

Tlie  enamel  is  a  hard  white  substance  which  protects  the  crown  of  a 
tooth,  being  thickest  at  the  cutting  edge.  It  is  the  hardest  part  of  the 
tooth,  and  consists  of  hexagonal  rods,  parallel  and  presenting  one  end  to 
the  dentine,  the  other  to  the  crown.  It  also  presents  a  series  of  brown 
lines,  the  parallel  striae. 

The  crusta  petrosa  covers  the  dentine  of  the  root,  which  has  no 
enamel..  It  resembles  true  bone  of  a  somewhat  modified  structure,  con- 
taining lacunae,  lamellae,  canaliculi,  and  some  Haversian  canals. 


320  THE   ORGANS   OF   DIGESTION. 

Give  the  different  periods  of  eruption  of  the  different  teeth. 

The  period  of  eruption  for  the  temporary  teeth  is  from  the  seventh 
month  to  the  end  of  the  second  year.  They  appear  in  the  following 
order :  central  incisors,  lateral  incisors,  anterior  molars,  canines,  posterior 
molars.  The  lower  precede  the  upper  by  a  short  period.  The  perma- 
nent teeth  appear  as  follows :  between  the  sixth  and  seventh  year,  first 
molars ;  seventh  year,  middle  incisors ;  eighth  year,  lateral  incisors ; 
ninth  year,  first  bicuspids;  tenth  year,  second  bicuspids;  eleventh  to 
twelfth  year,  canine ;  twelfth  to  thirteenth  year,  second  molars ;  seven- 
teenth to  twenty-first  year,  wisdom  teeth. 

THE  PALATE. 
Describe  the  palate. 

The  palate  forms  the  roof  of  the  'mouth,  and  consists  of  a  front  part 
or  hard,  and  a  back  part  or  soft  palate.  The  periosteum  of  the  hard 
palate  (see  Bones)  is  covered  by  and  intimately  connected  with  the 
mucous  membrane  of  the  mouth.  In  the  middle  line  is  a  raphe  ending 
in  front  at  a  small  papilla,  which  marks  the  anterior  palatine  fossa  which 
receives  the  terminal  part  of  the  anterior  palatine  and  naso- palatine 
nerves.  The  mucous  membrane  is  pale  and  corrugated,  covered  with 
squamous  epithelioma,  and  furnished  with  a  number  of  palatal  glands 
which  lie  between  it  and  the  bone. 

Describe  the  soft  palate  (velum  pendulum  palati). 

It  partially  separates  the  mouth  and  pharynx.  It  consists  of  muscu- 
lar, connective,  and  adenoid  tissue,  with  vessels,  nerves,  and  mucous 
glands,  all  enclosed  in  a  fold  of  mucous  membrane.  Above  it  is  joined  to 
the  back  of  the  hard  palate ;  laterally  it  blends  with  the  pharynx ;  below 
it  is  free ;  in  front  it  is  concave,  with  a  median  ridge ;  and  behind  it  is 
convex.  Its  mucous  membrane  is  continuous  with  that  of  the  roof  of 
the  mouth  and  of  the  posterior  nares. 

From  its  lower  border  a  conical  process  depends,  the  uvula,  from  whose 
base  descend  th^  pillars  of  the  soft  palate,  the  anterior,  formed  by  the 
palaio-glosd  muscles^  to  the  sides  of  the  base  of  the  tongue ;  the  pos- 
terior, formed  by  the  palato-pharyngei^  to  the  sides  of  the  pharynx. 
These  pillars  are  covered  by  mucous  membrane  and  separated  below  by 
the  tonsil,  the  space  being  called  the  isthmus  of  the  fauces.  The  mus- 
cles of  the  soft  palate  are  five  on  each  side,  and  lie  in  the  following  rela- 
tive position^  from  before  backward :  the  palato-glossus,  tensor  palati, 
anterior  fasciculus  of  palato-pharyngeus.  levator  palati,  azj^gos  uvulae, 
and,  lastly,  the  posterior  fasciculus  of  the  palato-pharyngeus. 

THE  TONSILS. 
Describe  the  tonsils. 

^  The  tonsils  (amygdalae)  lie  between  the  anterior  and  posterior  pala- 
tine pillars,  and  are  about }  inch  long  and  J  inch  wide  and  thick,  but  vary 


THE   SALIVARY   GLANDS.  321 

much  in  size.  Externally  they  are  separated  by  the  superior  constrictors 
from  the  internal  carotid  and  ascending  pharyngeal  arteries ;  internally 
they  project  into  the  fauces,  and  present  twelve  or  more  orifices  which 
lead  into  the  crypts  in  their  substance.  Around  the  crypt-walls  are 
numerous  lymphoid  follicles  consisting  of  adenoid  tissue. 

THE  SALIVARY  GLANDS. 
Describe  the  salivary  glands. 

There  are  three  pairs,  parotid^  suhmaxiUary^  and  suhlingual. 

The  parotid,  the  largest,  weighs  }  to  1  ounce,  and  lies  on  the  face 
below  and  in  front  of  the  ear.  its  outer  surface,  lobulated,  is  covered 
by  the  skin  and  fascia,  and  partly  by  the  platysma  and  several  lymphatic 
glands ;  in  front  it  runs  over  the  masseter,  is  grooved  for  the  ramus  of 
the  lower  jaw,  and  extends  beneath  it,  between  the  two  pterygoids; 
above  it  is  bounded  by  the  zygoma ;  below  by  the  angle  of  the  jaw  and 
a  line  joining  it  with  the  mastoid  process ;  behind  by  the  external  mea- 
tus, mastoid  process,  and  sterno-mastoid.  The  internal  surface  sends 
two  processes  into  the  neck :  one  behind  the  styloid  process  and  beneath 
the  mastoid  process  and  sterno-mastoid ;  another  in  front  of  the  styloid 
process,  into  the  back  of  the  glenoid  cavity  behind  the  jaw.  Imbedded 
in  the  gland  are  found  the  external  carotid,  posterior  auricular,  tempo- 
ral, transverse  facial,  and  internal  maxillary  arteries,  the  temporo-maxil- 
lary  vein  and  a  branch  from  it  to  the  internal  jugular,  the  facial  nerve 
with  its  branches;  and  the  auriculo-temporal  and  great  auricular  nerves. 
The  internal  carotid  artery  and  internal  jugular  vein  lie  under  its  deep 
surface. 

The  duct  (Stenson's)  is  about  2 J  inches  long  and  \  inch  in  diameter, 
and  opens  opposite  the  second  molar  tooth,  thence  runs  backward  be- 
neath the  mucous  membrane,  through  the  buccinator,  and  across  the 
masseter  to  the  front  of  the  gland.  It  commences  by  numerous  branches, 
and  on  the  masseter  receives  the  duct  of  a  detached  part  of  the  gland, 
the  soda  parotidis,  which  sometimes  is  found  beneath  the  zygomatic 
arch.     Its  epithelium  is  columnar. 

The  submaxillary  gland  is  of  an  irregular  form,  weighs  about  2 
drachms,  and  lies  below  the  jaw  and  above  the  digastric  niuscle.  It  is 
covered  by  the  skin,  platysma,  and  fasciae,  and  grooves  the  inner  surface 
of  the  lower  jaw.  It  lies  on  the  mylo-hyoid  (partially  embracing  this 
muscle),  hyoglossus,  and  styloglossus,  and  has  in  front  of  it  the  anterior 
belly  of  the  digastric.  Behind,  the  stylo-maxillary  ligament  separates  it 
from  the  parotid,  and  the  mylo-hyoid  (its  superficial  part)  from  the  sub- 
lingual gland  in  front.    The  lacial  artery  grooves  its  upper  and  back  part. 

The  suhmaxiJIary  duct  (Wharton's)  is  2  inches  long,  and  opens  at  the 
top  of  a  papilla  close  to  the  fraenum  hnguae.  Thence  it  runs  back  be- 
tween the  sublingual  gland  and  the  genio-hyoglossus,  then  between  the 
mylo-hyoid  and  the  hyoglossus  and  genio-hyoglossus. 

The  sublingual  gland,  the  smallest  of  the  salivary  glands,  lies  at  the 
21— A. 


322  THE   ORGANS   OF   DIGESTION. 

side  of  the  fraenum  linguae  and  against  the  inner  surface  of  the  lower 
jaw,  beneath  the  mucous  membrane.  It  is  almond-shaped,  weighs  1 
drachm,  and  its  ducts  (of  Rivini),  ten  to  twenty  in  number,  open  sepa- 
rately, one  or  two  joining  to  form  the  duct  of  Bartholin,  which  joins 
•Wharton's  duct.  It  is  in  relation  below  with  the  mylo-hj^oid ;  in  front 
with  its  fellow  and  the  lower  jaw ;  behind  with  the  submaxillary  gland ; 
internally  the  gustatory  nerve  and  Wharton's  duct  separate  it  from  the 
genio-hyoglossus. 

THE   PHARYNX. 

Describe  the  pharynx. 

The  pharynx  extends  from  the  base  of  the  skull  to  the  lower  border 
of  the  cricoid  cartilage ;  it  is  4i  inches  long,  wider  transversely  than 
antero-posteriorly,  and  widest  opposite  the  hyoid  cornua.  Below  it 
opens  into  the  oesophagus ;  above  it  is  connected  with  six  openings — 
viz.  the  mouth,  larynx,  the  two  posterior  nares,  and  the  two  Eustachian 
tubes. 

The  pharynx  is  formed  of  a  fibrous  coat,  the  pharyngeal  aponeurosis, 
thick  above,  thinner  below,  lined  by  mucous  membrane  and  covered  by 
muscles.  Above  it  is  connected  with  the  body  of  the  sphenoid  and  the 
basilar  process  of  the  occipital  bone ;  behind  with  the  spine,  the  longi  colli 
and  recti  capitis  antici  muscles ;  in  front  with  the  internal  pterygoid  plate, 
pterygo-maxillary  ligament,  lower  jaw,  tongue,  larynx,  and  os  hyoides ; 
laterally  are  the  styloid  processes  and  their  muscles,  common  and  internal 
carotid  arteries,  internal  pterj^goid  muscles,  internal  jugular  veins,  and 
the  glosso-pharyngeal,  vagus,  hypoglossal,  and  sympathetic  nerves. 
The  pharyngeal  aponeurosis  is  strengthened  behind  by  a  fibrous  band 
which  forms  a  median  raphe,  and  is  attached  above  to  the  pharyngeal 
spine  on  the  basilar  process  of  the  occipital.  Into  it  are  inserted  the 
constrictores  pharyngis.  A  mass  of  lymphoid  tissue  at  the  back  of  the 
pharynx  has  been  called  the  pharyngeal  tonsil. 

THE  OESOPHAGUS. 
Describe  the  oesophagus. 

The  oesophagus  is  the  tube  connecting  the  pharynx  with  the  stomach, 
and  extends  from  the  level  of  the  sixth  cervical  vertebra  through  the 
diaphragm,  entering  the  stomach  opposite  the  tenth  or  eleventh  dorsal 
vertebra,  a  distance  of  9  or  10  inches.  At  first  in  the  median  line,  it 
runs  to  the  left  as  far  as  the  root  of  the  neck,  becomes  again  mesial,  and 
lastly  turns  toward  the  left  to  pass  through  the  oesophageal  orifice  in  the 
diaphragm.  It  also  corresponds  to  the  cervical  and  dorsal  curves  of  the 
spine.  It  is  the  narrowest  part  of  the  alimentary  canal,  and  presents 
two  constrictions,  one  at  its  commencement,  the  other  at  the  diaphragm. 

In  the  neck  it  is  in  relation,  in  fronts  with  the  trachea ;  behind,  with 
the  longus  colli  and  spinal  colunm ;  laterally^  with  the  common  carotid 


THE   STOMACH.  323 

arteries  and  part  of  the  thyroid  gland.     Between  it  and  the  trachea 
ascend  the  recurrent  laryngeal  nerves. 

In  the  chest  it  is  in  relation,  in  fronts  with  the  trachea,  left  carotid 
artery,  left  bronchus,  and  pericardium ;  behind,  with  the  spine,  longus 
colli,  thoracic  duct,  and  aorta ;  laterally,  with  the  pleurae,  and  on  the 
right  side  the  large  azygos  vein,  and  on  the  left  the  aorta.  The  right 
vagus  is  behind,  the  left  in  front  of,  the  oesophagus,  but  at  first  each  is 
on  the  corresponding  side. 

What  is  the  structure  of  the  oesophagus  ? 

The  oesophagus  has  an  external  muscular  coat,  which  is  composed  of 
an  external  longitudinal  and  an  internal  circular  layer,  an  areolaT  coat 
between,  and  an  internal  mucous  coat.  This  last  is  thick,  paler  below, 
and  marked  by  longitudinal  folds.  Its  surface  presents  numerous  pa- 
pillae and  is  covered  by  stratified  epithelium.  Beneath  it  is  a  muscularis 
mucosae,  and  in  the  submucous  or  areolar  coat  are  numerous  compound 
racemose  oesophageal  glands. 

THE   STOMACH. 

Describe  the   stomach  ~  situation,  measurements,   orifices,   and 
borders. 

The  stomach  lies  in  the  epigastric  and  left  hypochondriac  regions,  and 
is  the  most  dilated  part  of  the  alimentary  canal.  Its  shape  is  pyriform, 
the  left  or  larger  end  being  called  the  cardiac,  the  right  the  pyloric  end. 
The  left  and  right  openings  are  termed  respectively  the  cardiac  or 
oesophageal  orifice  and  the  pyloric  orifice.  In  a  state  of  moderate  dis- 
tension it  is  12  inches  long  and  4  inches  in  its  vertical  diameter,  and 
weighs  4  to  5  ounces. 

The  cardiac  orifice  is  the  highest  part  of  the  stomach,  and  lies  behind 
the  seventh  costal  cartilage,  1  inch  to  the  left  of  the  sternum ;  the  pyloric 
orifice  is  guarded  by  a  valve,  the  pylorus.  Between  the  two  the  stomach 
is  curved,  the  upper  concave  border  being  known  as  the  lesser,  the  lower 
convex  border  as  the  greater,  curvature.  The  former  gives  attachment 
to  the  lesser,  the  latter  to  the  great  omentum.  The  left  end  (greater  or 
splenic)  extends  2  or  3  inches  to  the  left  of  the  cardiac  orifice,  forming 
the  fundus  or  great  cul-de-sac.  The  gastro-splenic  omentum  connects  it 
to  the  spleen.  The  lesser  or  pyloric  end  lies  inferior  and  anterior  to  the 
fundus,  in  contact  with  the  liver  and  bellj^-wall,  and  its  position  varies 
according  to  the  state  of  distension. 

Describe  the  relations  of  the  stomach. 

Anterior  Surface. 
Diaphragm. 

Under  surface  of  left  lobe  of  liver. 
Abdominal  wall. 


324  THE  ORGANS   OF   DIGESTION. 

Right  End.  Left  End. 

Abdominal  wall.  ^  Lower  ribs. 

Under  surface  of  right  lobe  of  liver.  Spleen  (and  behind). 

Posterior  Surface. 
Pancreas  and  pancreatic  vessels. 
Abdominal  aorta  and  inferior  cava. 
Coeliac  axis  and  branches. 
Crura  of  diaphragm  and  solar  plexus. 
Superior  mesenteric  vessels. 
Left  kidney  and  capsule. 
Spleen. 

[Below.) 
Transverse  colon  and  transverse  mesocolon,  upper  layer. 

Describe  the  structure  of  the  stomach. 

The  stomach  has  a  serous  peritoneal  coat,  a  muscular  coat  comprising 
a  longitudinal,  circular,  and  oblique  layer,  an  areolar  coat  of  loose 
tissue  (submucous  coat),  and  a  mucous  coat.  The  latter  is  thickest  near 
the  pylorus,  thinnest  at  the  fundus,  and  presents,  in  the  empty  condition 
of  the  organ,  numerous  ridges  or  rugce  which  run  longitudinally  along 
the  great  curvature.  Studded  over  its  surface  are  many  small  polygonally^ 
shaped  depressions  which  are  the  enlarged  mouths  of  the  gastric  tubular 
glands.  These  are  of  two  kinds,  called  pyloric  and  peptic  glands ;  some 
are  simply  tubular,  while  others  have  several  branches  opening  into  a 
common  duct.  The  pyloric  glands  are  most  numerous  at  the  smaller 
end,  but  the  peptic  glands  are  found  all  over  the  stomach,  the  ducts  of 
the  latter  being  shorter.  In  the  latter,  between  the  basement  membrane 
and  the  lining  epithelium,  are  numerous  peptic  or  parietal  cells,  the  others 
being  known  as  the  central  or  chief  cells.  Between  the  glands  the  mucous 
membrane  contains  lymphoid  tissue,  collected  here  and  there  into  little 
masses  resembling  the  solitary  intestinal  glands,  and  called  the  lenticular 
glands.     Beneath  the  membrane  is  a  muscularis  mucosae. 

THE   SMALL   INTESTINE. 

Describe  the   small  intestine— situation,  division,   and  attach- 
ments. 

The  small  intestine  is  about  20  feet  long,  and  is  a  convoluted  tube 
which  forms  that  part  of  the  alimentary  canal  between  the  pylorus  and 
the  caecum.  It  occupies  the  central  and  lower  part  of  the  abdomen  and 
part  of  the  pelvis,  and  is  surrounded  by  the  large  gut,  being  held  in 
position  by  the  peritoneal  fold  called  the  mesentery,  which  is  attached 
behind  to  the  spine.  It  is  covered  in  front  by  the  great  omentum,  and 
is  divided  into  three  parts,  the  duodenum,  jejunum,  and  ileum. 


THE  SMALL   INTESTINE.  325 

Describe  the  structure  of  the  small  intestine. 

The  small  intestine  is  made  up  of  four  coats : 

An  external  pei'itoneal  coat,  which  completely  invests  the  jejunum  and 
ileum  except  at  the  mesenteric  or  attached  border  behind,  where  the 
vessels  pass,  and  which  only  partially  invests  the  duodenum.  Of  this 
latter,  the  first  portion  is  completely  invested,  the  second  portion  only  in 
front,  and  the  third  is  covered  in  front  by  peritoneum  derived  from  the 
inferior  layer  of  the  transverse  mesocolon. 

The  muscular  coat  consists  of  an  internal  circular  and  an  external  lon- 
gitudinal layer. 

The  areolar  or  submucous  coat  consists  of  loose  connective  tissue  sup- 
porting the  vessels. 

The  mucous  membrane  is  closely  covered  by  villi,  and  is  of  a  red  color 
at  the  upper  part,  but  thinner  and  paler  below.  Its  epithelium  is  co- 
lumnar, and  it  is  furnished  with  a  muscularis  mucosce.  The  prominent 
features  of  the  mucous  membrane  are  (a)  valvules  conniventes  (Kerk- 
ring's),  crescentic  transverse  folds  extending  one-half  or  two-thirds 
around  the  circumference,  the  largest  being  2J  inches  long  and  J  inch 
wide.  These  folds  are  found  from  a  point  1  to  2  inches  from  the  pylorus 
to  about  midway  through  the  ileum,  [b)  The  villi.,  small  projections  set 
closely  together  over  the  entire  mucous  membrane  surface  of  the  small 
intestine,  and  about  -^  inch  long.  Each  villus  consists  of  a  projection  of 
the  mucous  membrane  enclosing  blood-vessels,  a  lacteal,  and  a  part  of 
the  muscularis  mucosae,  all  held  together  by  lymphoid  tissue  and  sur- 
rounded by  a  delicate  basement  membrane  beneath  the  epithelium,  (c) 
Lieberkilhns  follicles.  These  are  small  tubes  found  everywhere  in  the 
mucous  membrane,  and  consist  of  a  basement  membrane  hned  by  a  layer 
of  epithelium,  {d)  Brunner^s  glands  are  small  granular  bodies  in  the 
submucous  tissue,  their  ducts  opening  on  the  mucous  surface.  They  are 
found  only  in  the  duodenum  and  the  commencement  of  the  jejunum. 
(e)  The  solitary  glands  are  small  whitish  bodies,  most  numerous  in  the 
lower  part  of  the  ileum.  They  are  made  up  of  very  vascular  retiform 
tissue,  and  on  their  surfaces  are  found  villi  and  around  them  the  openings 
of  Lieberkuhn's  glands.  (/)  Peyer  s  patches  are  oblong  aggregations  of 
solitary  glands,  measuring  from  J  inch  to  4  inches  in  length,  and  are 
situated  on  the  border  opposite  to  the  attachment  of  the  mesentery. 
Their  surface  is  not  covered  by  villi,  and  they  are  surrounded  by  Lieber- 
kuhn's crypts.     They  are  most  numerous  in  the  lower  part  of  the  ileum. 


Give  a  general  description  of  the  duodenum. 

The  duodenum  is  about  10  inches  long  (12  fingers),  and  runs  in  a 
curved  direction  from  the  pylorus  to  the  jejunum,  which  it  joins  on  the 
left  side  of  the  second  lumbar  vertebra.  The  concavity  of  the  curve 
looks  toward  the  left  and  embraces  the  head  of  the  pancreas.  It  is 
divided,  for  description,  into  three  parts. 


326  THE   ORGANS   OF   DIGESTION. 

Name  these  three  parts,  and  give  the  relations  of  each. 
First  or  Ascending  Portion. 

Above  and  Front 
Liver. 
Neck  of  gall-bladder. 

Behind. 
Hepatic  artery. 
Com.  bile-duct. 
Vena  portae. 

Below. 
Part  of  head  of  pancreas. 

Second  or  Descending  Portion. 
Front 
Hepatic  flexure  of  colon. 
Transverse  mesocolon. 
Pancreatico-duod.  arteries. 

Behind. 

Right  kidney  and  suprarenal  capsule  (at  times).  ' 

Structures  at  hilus  of  kidney. 

Com.  bile  duct  (and  to  left).  •  '^ 

Internally. 
Head  of  pancreas. 

Third  or  Transverse  Portion. 

Above. 

Inf.  border  of  pancreas. 
Sup.  mesenteric  vessels. 

Front 

Peritoneum  derived  from  descending  layer  trans,  mesocolon. 
Sup.  mesenteric  vessels. 

Behind. 
Aorta  and  inf.  cava. 
Crura,  diaphragm. 
Second  lumbar  vert. 

Describe  the  jejunum  and  ileum. 
The  j^unum  includes  the  first  two-fifths  of  the  remaining  part  of  the 


THE   LARGE   INTESTINE.  327 

small  intestine,  running  from  the  left  side  of  the  second  lumbar  vertebra 
to  the  beginning  of  the  ileum,  and  occupying  the  umbilical  and  left 
lumbar  and  iliac  regions.  Its  coats  are  thicker  and  more  vascular,  and 
it  is  of  a  deeper  color  and  larger  calibre,  than  the  ileum. 

The  remainder  of  the  small  intestine  is  the  ileum^  which  ends  by  open- 
ing into  the  inner  side  of  the  commencement  of  the  large  gut  in  the 
right  iliac  fossa.  Its  coils  occupy  the  hypogastric,  umbilical,  and  right 
lumbar  and  iliac  regions. 

THE  LARGE  INTESTINE. 

Describe  the  large  intestine. 

The  large  intestine  is  that  part  of  the  alimentary  canal  which  extends 
from  the  end  of  the  ileum  to  the  anus ;  it  is  about  5}  feet  long,  and  sur- 
rounds the  small  intestine.  It  commences  by  a  dilated  part,  the  caecum^ 
in  the  right  iliac  fossa,  ascends  to  the  under  surface  of  the  liver,  then  runs 
transversely  across  the  abdomen  to  the  vicinity  of  the  spleen,  descends 
to  the  left  iliac  fossa,  and  forms  the  sigmoid  flexure,  and  finally  passes 
along  back  of  the  pelvis  to  end  at  the  anus. 

What  is  the  caecum  ? 

The  caecum  is  the  large  cul-de-sac  which  is  the  beginning  of  the  large 
intestine,  and  is  about  3  inches  broad  and  2}  long.  It  is  variously  situated, 
being  found  on  the  psoas,  external  to  it,  on  the  iliacus,  internal  to  it,  on 
the  pelvic  brim,  or  entirely  within  the  pelvis.  In  any  of  these  positions 
it  is  entirely  surrounded  by  peritoneum. 

Describe  the  vermiform  appendix. 

From  the  inner  and  back  part  of  the  caecum,  at  its  lower  end,  the  ver- 
miform appendix  extends  upward  and  inward  behind  it.  This  is  a  piece 
of  gut  of  the  diameter  of  a  goose-quill,  varying  from  3  to  6  inches  in 
length,  curved  upon  itself,  and  ending  in  a  blind  extremity.  It  tapers 
gradually  to  its  end,  which  is  blunt,  is  completely  invested  by  the  peri- 
toneum, which  forms  for  it  a  mesentery,  and  at  its  connection  with  the 
caecum  is  guarded  by  an  imperfect  valve. 

Describe  the  ilio-caecal  valve. 

The  small  intestine  opens  into  the  large  gut  about  2}  inches  above  the 
lower  extremity  of  the  caecum  in  an  oblique  direction.  Its  opening  is 
guarded  by  a  double  fold  forming  the  iJeo-ccecal  valve,  which  lies  trans- 
versely to  the  long  axis  of  the  colon.  Each  fold  of  the  valve  is  made 
up  of  the  mucous  and  submucous  coats,  reinforced  by  some  circular  fibres 
from  the  muscular  coat,  of  each  portion  of  the  gut,  and  is  covered  on 
the  side  toward  the  ileum  with  villi.  At  each  end  of  the  opening  these 
folds  run  together  and  are  prolonged  some  distance  around  the  gut,  form- 
ing the  retinacula. 


328  THE  ORGANS   OF   DIGESTION. 

Describe  the  ascending  colon. 

This  part  of  the  large  gut  runs  from  the  caecum,  above  the  ileo- 
caecal  valve,  upward  to  the  under  surface  of  the  liver  on  the  right  side 
of  the  gall-bladder,  and  then  turns  forward  and  to  the  left  to  form  the 
hepatic  flexure.  The  peritoneum  rarely  forms  for  it  a  mesocolon  ;  gene- 
rally it  covers  only  the  front  part  and  the  sides.  It  occupies  the  right 
lumbar  and  hypochondriac  regions. 

Describe  the  transverse  colon. 

This  part  arches  across  the  abdomen,  the  convexity  looking  toward  the 
belly-wall,  and  makes  a  sudden  turn  backward  and  downward  beneath  the 
spleen,  forming  the  splenic  flexure,  and  is  completely  invested  by  the  peri- 
toneum. It  occupies  the  right  hypochondriac,  upper  part  of  umbilical 
and  left  hypochondriac  regions.  At  the  splenic  flexure  is  attached  the 
costo-colic  ligament,  a  fold  of  peritoneum  extending  to  the  diaphragm 
opposite  the  tenth  or  eleventh  rib. 

Describe  the  descending  colon. 

This  part  descends  from  the  splenic  flexure,  to  end  at  the  left  iliac 
fossa  in  the  sigmoid  flexure.  It  is  covered  in  front  and  laterally  by  the 
peritoneum.     It  occupies  the  left  hypochondriac  and  lumbar  regions. 

Give  the  relations  of  each  of  the  three  portions  of  the  colon. 

First  or  Ascending  Portion. 

Front. 
Ileum. 

Abdom.  wall. 
Great  omentum. 

Behind. 
Quadratus  lumborum. 
Right  kidney  (lower  part). 
Second  portion  duod.  (hepatic  flexure). 

Second  or  Transverse  Portion. 

Ahove. 
Liver  and  gall-bladder. 
Stomach  (gt.  curvature). 
Splenic     f  Spleen  (lower  end), 
flexure.  |  Pancreas  (tail). 

Below. 
Small  intestines. 


THE   KECTUM.  329 

Behind. 
Transverse  mesocolon. 

Third  or  Descending  Portion. 

Front. 
Jejunum. 
Abdom.  wall. 

Behind. 
Left  kidney  (along  left  border  of  lower  part  ant.  surface). 
Quadratus  lumborum. 

Describe  the  sigmoid  flexure. 

The  sigmoid  flexure  ends  in  the  rectum.  From  the  end  of  the  de- 
scending colon  it  forms  an  S-shaped  curve,  ending  opposite  the  left  sacro- 
ihac  joint.  In  front  of  it  are  the  belly- wall  and  some  coils  of  small  in- 
testine. The  peritoneum  forms  a  loose  mesocolon  for  it.  It  is  the 
narrowest  part  of  the  colon. 

Describe  the  rectum. 

The  rectum  is  the  lowest  part  of  the  large  intestine,  and  extends  from 
the  sigmoid  flexure  to  the  anus.  It  has  been  divided  into  three  parts : 
the  first  part  extends  from  the  left  sacro-iliac  joint  to  the  centre  of  the 
third  piece  of  the  sacrum ;  the  second  part,  to  the  tip  of  the  coccyx ; 
and  the  third  part,  to  the  anus. 

The  rectum  is  about  8  inches  long  and  somewhat  cjdindrical  in  form, 
narrower  above  than  the  sigmoid  flexure,  but  it  enlarges  as  it  descends, 
and  just  above  the  anus  is  remarkably  dilated,  forming  the  ampulla. 
The  first  part  has  a  mesorectum  ;  the  second  part  is  covered  by  perito- 
neum in  front  and  laterally ;  the  third  part  has  no  peritoneal  covering. 

Give  the  relations  of  the  first  and  second  part  of  the  rectum. 

The  first  part  of  the  rectum  is  about  one-half  of  its  whole  length, 
and  has  the  following  relations: 

Behind. 
Pyriformis, 

MiaiTrtoy  and  branches,  }  ^^  ^^^  ^^^  ^^^^  ^^'^^^' 

Front. 

Male.  Female. 

Post,  surface  of  bladder.  Post,  surface  of  uterus  and 

appendages. 
(Small  intestines  intervening  in  both  cases.) 


330  THE   ORGANS   OF   DIGESTION. 

The  second  part  is  about  3  inches  long,  and  has  the  following  re- 
lations : 

Behind. 

Concavity  of  sacrum. 
Middle  sacral  artery. 

Front. 
Male,  Female. 

Triangular  part  of  bladder.  Post,  vaginal  wall. 

VesiculaB  seminales.  Cervix  uteri. 

Vas  deferens. 
Under  surface  of  prostate. 

Describe  the  third  or  lower  part  of  the  rectum,  and  give  its 
relations. 

The  third  part  is  1  to  1 J  inches  long,  and  curves  backward  and  down- 
ward to  end  at  the  anus,  where  it  is  surrounded  by  the  external  sphinc- 
ter. Higher  up  the  internal  sphincter  surrounds  it,  and  the  levatores 
ani  support  it  on  each  side,  in  front  of  it  are  the  membranous  and 
bulbous  portions  of  the  urethra,  but  separated  from  it  by  a  triangular 
cellular  space  whose  base  is  the  central  point  of  the  perineum.  In  the 
female,  in  front,  vagina  and  perineal  body. 

Describe  the  structure  of  the  large  intestine. 

It  has  four  coats — serous,  muscular,  submucous,  and  mucous. 

The  serous  coat  is  peritoneum,  and  along  the  anterior  margin  of  the 
gut  it  presents  numerous  little  projections  called  appendices  epiploicae, 
which  are  filled  with  fat. 

The  muscular  coai  is  divided  into  two  layers,  longitudinal  and  circular, 
the  former  being  external.  The  circular  layer  is  disposed  generally  over 
the  surface. 

The  loiigitudmal  layer  is  seen  as  three  well-marked  bands  J  inch  wide 
and  J  line  thick.  These  bands  commence  on  the  caecum  at  the  origin 
of  the  vermiform  appendix,  and  have  the  following  arrangement  on  the 
three  divisions  of  the  colon  respectively:  the  anterior  band  runs  along 
the  anterior  border  of  the  ascending,  the  transverse,  and  descending 
colon:  this  band  serves  for  the  attachment  of  the  great  omentum  to 
the  transverse  colon;  the  postenor  band  extends  along  the  posterior 
border  of  the  entire  colon,  and  indicates  the  line  along  which  the  perito- 
neum leaves  the  ascending  and  descending  colon,  and  along  the  trans- 
verse colon  it  is  the  line  of  coalescence  of  the  two  layers  of  the  trans- 
verse mesocolon ;  the  inner  band  is  on  the  inner  border  of  the  ascending 
and  descending  colon  and  on  the  under  border  of  the  transverse  colon. 
It  is  along  this  band  that  the  appendices  epiploicae  are  found. 

The  submucous  coat  is  made  up  of  areolar  tissue. 


THE   LIVER.  331 

The  mucous  coat  or  mucous  membrane  is  smooth,  has  no  villi,  con- 
tains crypts  of  Lieberklihm,  and  has  lymphoid  nodules  scattered  over  its 
surface. 

What  can  you  say  of  the  structure  of  the  rectum  ? 

The  longitudinal  fibres  of  its  muscular  coat  are  disposed  in  a  uniform 
layer.  There  are  no  bands.  The  mucous  membrane  has  numerous  folds, 
which  near  the  anus  are  longitudinal  in  direction  and  are  known  as  the 
columns  of  Morgagni.  At  and  above  the  level  of  the  prostate  gland 
there  are  three  other  prominent  folds,  having  more  or  less  a  horizontal 
direction.     These  are  called  the  folds  of  Houston. 

THE   LIVER. 
Give  the  general  position  and  measurements  of  the  liver. 

The  liver  lies  in  the  epigastric  and  right  hypochondriac  region,  reach- 
ing partly  into  the  left  hypochondrium,  weighs  betw^een  3  and  4  pounds, 
and  measures  10  to  12  inches  transversely,  6  to  7  inches  from  before 
backward,  and  3J  inches  vertically  at  its  thickest  part. 

Give  the  relations  of  the  liver. 

Above. 
Diaphragm. 
Abdom.  wall. 

Below. 
Stomach,  duodenum  (first  part). 
Hepatic  flex,  colon. 
Right  kidney  and  suprarenal  capsule. 
Grail- bladder  and  duct  (cystic). 

Behind. 
Diaphragm. 
Aorta  and  inf  cava. 

How  is  the  liver  divided  ? 

The  upper  surface  is  divided  by  the  suspensory  ligament,  and  the  lower 
by  the  longitudinal  fissure,  into  a  right  and  a  left  lobe.  The  anterior 
thin  border  is  notched  opposite  the  suspensory  ligament.  The  right  ex- 
tremity is  thick,  the  left  thin  and  flattened. 

Name  and  describe  the  ligaments  of  the  liver. 

They  are  all  peritoneal  folds  excepting  the  round  ligament,  which  is  a 
foetal  remnant.  The  longitudinal  (suspensory  or  broad)  ligament  is  broad 
and  thin,  runs  from  before  backward,  and  is  attached  above  to  the  dia- 
phragm and  sheath  of  the  right  rectus  muscle  as  far  as  the  umbilicus ; 
below  to  the  superior  surface  of  the  liver,  from  the  posterior  border  to 
the  notch  in  the  anterior  border.     The  free  anterior  border  has  between 


332  THE   ORGANS   OF   DIGESTION. 

its  layers  the  round  ligament^  which  is  the  shrivelled  and  impervious 
remains  of  the  foetal  umbilical  vein.  It  runs  along  the  longitudinal  fis- 
sure from  the  umbilicus  to  the  vena  cava.  The  lateral  ligaments  are 
peritoneal  folds  which  extend  between  the  diaphragm  and  the  corre- 
sponding borders  of  the  liver,  the  left  being  to  the  left  of  the  oesoph- 
ageal opening.  The  coronary  ligament  is  a  process  of  peritoneum  which 
is  reflected  on  to  the  posterior  surface  of  the  liver  in  the  situation  of  its 
apposition  with  the  diaphragm.  It  is  continuous  with  the  lateral  liga- 
ments on  each  side  and  with  the  suspensory  in  front. 

Name  and  describe  the  fissures  of  the  liver. 

They  are  five.  The  longitudmal  separates  the  right  and  left  lobes. 
It  is  joined  by  the  transverse  fissure,  the  part  in  front  of  that  point  being 
called  the  umbilical  Jismre,  and  lodging  the  umbilical  vein  or  its  remains, 
the  round  ligament.  The  Jissure  of  the  ductus  venosus  is  the  part  of  the 
longitudinal  fissure  behind  the  transverse.  It  lodges  the  ductus  veno- 
sus or  its  remains.  The  transverse  or  portal  Jissure  is  the  point  of  exit 
and  entrance  of  the  vessels,  nerves,  and  ducts.  It  hes  between  the  quad- 
rate and  Spigelian  lobes.  The  fissure  for  the  gall-bladder  is  parallel  to 
the  longitudinal  on  the  under  surface  of  the  right  lobe.  The  fissure  for 
the  inferior  vena  cava,  sometimes  a  complete  canal,  lies  to  the  right  of 
the  Spigelian  lobule. 

Name  and  describe  the  lobes  of  the  liver. 

These  are  also  five  in  number.  The  right  is  the  largest,  being  six  times 
as  large  as  the  left,  and  is  separated  from  the  left  above  and  below  by  the 
suspensory  ligament  and  longitudinal  fissure  respectively,  and  in  front  by 
the  interlobar  notch.  Its  under  surface  is  marked  by  the  transverse  fissure 
and  that  of  the  gall-bladder,  and  its  posterior  surface  by  that  of  the  infe- 
rior vena  cava,  and  anteriorly  is  the  impressio  colica  for  the  hepatic  flexure, 
and  behind  another,  the  impressio  renalis,  for  the  right  kidney.  The  left 
lobe  is  flattened,  lies  in  the  epigastrium,  and  is  in  relation  below  with  the 
stomach.  The  lobm  quadratus  is  on  the  under  surface  of  the  right  lobe, 
and  is  bounded  in  front  by  the  free  surface  of  the  liver,  behind  by  the 
transverse  fissure,  on  the  right  by  the  fissure  for  the  gall-bladder,  on  the 
left  by  the  umbilical  fissure.  The  Spigelian  lobe  lies  behind  and  above 
the  preceding,  and  is  bounded  in  front  by  the  transverse  fissure,  on  the 
right  by  the  fissure  of  the  vena  cava,  and  on  the  left  by  the  fissure  for 
the  ductus  venosus.  The  caudate  lobe  runs  outward  from  the  base  of  the 
Spigelian  lobe  to  the  under  surface  of  the  right  lobe,  lying  between  the 
transverse  fissure  and  that  for  the  inferior  vena  cava. 

Describe  the  vessels  of  the  liver. 

The  hepatic  arteiy  and  portal  vein,  with  nerves  and  lymphatics,  pass 
to,  and  the  hepatic  ducts  pass  out  from,  the  transverse  fissure.  These 
are  all  situated  between  the  layers  of  the  lesser  omentum,  lying  in  the 


THE   GALL-BLADDER.  333 

following  relative  position :  the  duct  to  the  right,  the  artery  to  the  left, 
and  the  vein  between  them  and  on  a  posterior  plane.  They  are  all 
enclosed  in  some  loose  areolar  tissue,  Glisson's  capsule,  and  a  prolonga- 
tion of  this  tissue  accompanies  them  through  the  liver. 

The  hepatic  veins,  three  large  and  several  small,  empty  into  the  infe- 
rior vena  cava.  The  nerves  come  from  the  coeliac  plexus,  right  phrenic, 
and  both  vagi. 

THE   GALL-BLADDER. 
Describe  the  gall-bladder. 

This  is  a  pear-shaped  sac  lying  in  the  impression  of  the  right  lobe, 
from  the  right  end  of  the  transverse  fissure  to  the  anterior  free  margin. 
It  is  4  inches  long  and  IJ  inches  broad,  holding  8  to  12  drachms,  and 
is  held  in  place  by  areolar  tissue  and  the  peritoneum.  The  fundus  looks 
downward,  forward,  and  to  the  right ;  the  body  and  neck  upward,  back- 
ward, and  to  the  left. 

What  are  the  relations  of  the  gall-bladder  ? 

Body. 

Above, 
Liver. 

Below. 
Ascending  duod. 
Pyloric  end  of  stomach. 
Hepatic  flexure  of  colon. 

Fundus. 

Front 
Abdominal  wall  (ninth  or  tenth  costal  cart.). 

Behind. 
Transverse  colon. 

Describe  the  biliary  ducts. 

The  hepatic  duct  is  formed  by  the  junction  at  an  obtuse  angle  of  a 
branch  from  each  lobe,  and  runs  downward  and  to  the  right  for  nearly 

2  inches,  and  joins  the  cystic  duct  to  form  the  common  bile-duct.  The 
cystic  duct  is  IJ  inches  long,  and  descends  toward  the  left  and  joins  the 
above  as  described.     The  common  hile-duct  is  nearly  3  inches  long  and 

3  lines  in  diameter.  It  runs  along  the  right  border  of  ihQ  lesser  omen- 
tum behind  the  first  part  of  the  duodenum,  then  between  the  pancreas 
and  descending  duodenum,  then  to  the  right  of  the  pancreatic  duct,  with 
which  it  opens  by  a  common  orifice  at  the  summit  of  a  papilla  just  i3elow 
the  middle  of  the  inner  wall  of  the  second  portion  of  the  duodenum. 


334  THE   ORGANS   OF   DIGESTION. 

THE  PANCREAS. 
Describe  the  pancreas. 

This  is  a  long  gland,  flattened  from  before  backward,  tapering  to  its 
left  end,  the  tail^  and  enlarged  at  its  right  end,  the  head^  between  these 
two  points  being  the  body.  It  lies  in  the  back  part  of  the  epigastric 
and  left  hypochondriac  regions,  being  about  6  to  8  inches  long,  and  less 
than  1  inch  thick,  and  1 J  inches  broad.  Its  weight  is  variously  stated  at 
2  to  6  ounces. 

The  head  is  curved  upon  itself,  and  often  gives  off  a  projection  of  its 
substance  behind,  which,  with  the  remainder  of  the  organ,  encloses  the 
superior  mesenteric  vessels.  This  portion  is  sometimes  detached,  and  is 
called  the  lesser  pancreas.  The  pancreas  has  two  broad  surfaces,  ante- 
rior and  posterior,  and  a  narrow  inferior  surface. 

Give  the  relations  of  the  pancreas. 

Above. 

Cceliac  axis. 

Splenic  vessels  (vein  behind). 

Hepatic  artery. 

Front. 

Post,  surface  of  stomach. 

Peritoneum  derived  from  superior  layer  trans,  mesocolon. 

Right  Side.  '       Left  Side. 

Ascending  duod.  [above).  Spleen. 

Com.  bile-duct  {behind). 
Pancreatico-duod.  artery  {in  front). 
Descend  duod.  )    ^.^  „„„;„of 
Right  kidney.   |  abuts  agamst. 

Right  suprarenal  capsule  (behind). 
Trans,  duod.  (below).  - 

Behind. 
First  lumbar  vert. 
Crura  of  diaphragm. 
Sup.  mesenteric  vessels. 
Inf.  mesenteric  vein. 
Splenic  vein. 

Left  kidney  and  suprarenal  capsule. 
Left  renal  vessels. 
Thoracic  duct. 
Vena  portae. 
Aorta  and  inf  cava. 


THE   SPLEEN   AND   SUPRARENAL   CAPSULES.  335 

Below. 
Sup.  mesenteric  vessels. 
Inf.  mesenteric  vein. 
Splenic  flex,  colon. 
Transverse  duod. 
Peritoneum  derived  from  inferiorlayer  trans,  mesocolon. 

The  duct  of  the  pancreas  runs  from  left  to  right  and  empties  into  the 
duodenum  as  described.     It  is  called  the  duct  of  Wirsung. 

THE    SPLEEN  AND   SUPRARENAL    CAPSULES. 

THE   SPLEEN. 
Describe  the  spleen. 

The  spleen  is  placed  at  the  back  of  the  left  hypochondrium,  and  in  the 
axillary  line  extends  from  the  eighth  to  the  eleventh  rib.  It  is  oval  in 
shape,  highly  vascular,  of  a  pulpy  consistency,  very  brittle,  and  is  of  a 
peculiar  purplish  color.  The  anterior  surface  is  marked  by  a  vertical 
depression,  the  hilus,  which  affords  entrance  and  exit  to  the  vessels. 
Here  the  peritoneum,  which  invests  the  spleen,  passes  in  a  double  fold 
to  the  stomach  as  the  gastro-splenic  omentum. 

The  organ  consists  of  a  fibrous  trabecular  framework  containing  and 
supporting  the  red  splenic  pulp  and  the  vessels.  Within  the  pulp, 
scattered  here  and  there,  are  lighter-colored  bodies,  the  Malpighian  cor- 
puscles. These  are  developed  on  one  side  of  the  arterial  branches  or 
entirely  surround  these  vessels,  and  are  composed  of  lymphoid  tissue. 

What  are  the  relations  of  the  spleen  ? 

Externally  and  Posteriorly. 
Ninth,  tenth,  and  eleventh  ribs. 
Costo-phrenic  sinus  and  diaphragm. 

Above.  Below. 

Diaphragm.  Splenic  flexure  of  the  colon. 

Costo-colic  lig. 

Internally. 
Ant.  Part.  Post.  Part. 

Great  end  of  stomach,  Left  kidney  and  suprarenal  capsule. 

Tail  of  pancreas. 

THE   SUPRARENAL   CAPSULES. 
Describe  the  suprarenal  capsules. 

These  are  two  flattened  bodies,  in  shape  resembling  a  cocked  hat, 
which  lie  upon  the  upper  border  of  the  kidneys,  to  which  they  are  united 


336  THE   URINARY   ORGANS   AND   PERITONEUM. 

by  loose  areolar  tissue.  They  are  concave  below,  convex  above,  and 
marked  in  front  by  the  hilus,  from  which  emerges  the  suprarenal  vein. 
Each  measures  vertically  about  1}  inches,  transversely  H  inches,  and  is 
about  i  inch  thick.     They  weigh  each  about  2  drachms. 

Give  the  relations  of  the  suprarenal  capsules. 
Posteriorly. 
Diaphragm  at  junction  of  lumbar  and  costal  parts,  at  level  of  eleventh 
or  twelfth  dorsal  vertebra. 

Anteriorly. 
Right  Capsule.  Left  Capsule. 

Post,  surface  of  liver.  Spleen  at  upper  and  outer  end. 

Pancreas. 
Peritoneum  from  liver  to  ant.  sur-        Peritoneum  oflesser  sac  separating 
face  of  right  kidney.  it  from  cul-de-sac  of  stomach. 

Internally. 
Vena  cava  (sometimes).  Suprarenal  arteries  and  veins. 

THE  URINARY  ORGANS  AND  PERITONEUM. 

THE  KIDNEYS. 
Give  the  general  shape,  position,  and  measurements  of  the  kidneys. 

The  kidneys  lie  one  on  each  side  of  the  vertebral  column,  behind  the 
peritoneum,  opposite  the  last  dorsal  and  upper  two  or  three  lumbar 
vertebrae.  Each  is  bean-shaped,  measures  about  4  inches  in  length,  2i 
in  breadth,  and  1  to  1 J  inches  in  thickness,  and  weighs  about  4J  ounces. 
The  right  is  somewhat  lower  thaw  the  left,  as  well  as  somewhat  shorter 
and  broader. 

The  anterior  surface  of  the  kidney  is  convex  and  looks  somewhat  out- 
ward. 

Give  the  relations  of  the  kidneys. 

Front. 

( Right  kidney. )  ( Left  kidney. ) 

Post,  part  of  under  surface  r.  lobe  Great  end  of  stomach, 

of  liver.  Pancreas  in  the  middle. 

Descend,  duod.  (along  left  border).  Splenic  flexure  of  colon 

Hepatic  flexure  colon  (below).  (at  some  distance). 

Behind. 

Crus  diaphragm. 
Quadratus  lumborum. 
Psoas  (and  internally). 


THE  URETERS.  337 

Externally.  Internally. 

Abdom.  wall.  Vessels  at  hilus  and  ureter. 

Spleen  (left  kidney).  Psoas  magnus. 

Descend,  colon  (left  kidney).  [The  ureter  lies  behind  and  below 

the  vein  and  artery.  The  vein  is 
in  front  of  the  artery.] 

Above. 
Suprarenal  capsule  (somewhat  anteriorly  and  internally). 

Describe  the  structure  of  the  kidney. 

The  kidney  has  a  distinct  capsule,  beneath  which  is  some  unstriped 
muscle,  and  contains  within  it  a  central  cavity  or  sinus.  The  duct  or 
ureter  commences  by  a  dilated  part,  the  pelvis^  which  is  itself  made  up 
of  smaller  tubules,  the  calyces.  The  kidney  substance  is  made  up  of  a 
cortical  part  and  a  medullary  part.  The  latter  is  composed  of  pyramidal 
masses  of  a  darker-colored  tissue,  their  bases  looking  toward  the  periph- 
ery. They  contain  uriniferous  tubules  which  at  the  apices  of  the  pyra- 
mids open  into  the  calyces,  which,  in  turn,  make  up  the  pelvis. 

(For  a  more  detailed  description  of  the  structure  of  the  kidney,  see 
Histology  of  this  series.) 

THE    URETERS. 
Describe  the  ureters. 

These  tubes  convey  the  urine  from  the  kidneys  to  the  bladder.  Each 
is  16  to  18  inches  long,  of  the  diameter  of  a  goose-quill,  and  runs  down- 
ward, forward,  and  inward. 

What  are  its  relations  ? 

Front. 
Peritoneum. 
Spermatic  vessels. 

(Left  ureter)  sup.  hemorrhoidal  artery. 
Ileum  (right  ureter). 
Sigmoid  flex,  (left  ureter). 
Bladder. 

The  pelvis  of  the  ureter  is  on  a  level  posteriorly  with  the  spinous  pro- 
cess of  the  first  lumbar  vertebra. 

Behind.  Internally. 

Psoas.  ...  -^^^-  ^^^^  (right  ureter). 

Com.  iliac  artery  at  its  bifurcation.  Yas  deferens. 

Ureter  enters  post,  false  vesical  ligament,  with  vas  deferens  between  it 
and  the  bladder. 
22— A. 


338  THE   URINARY   ORGANS   AND   PERITONEUM. 

THE  BLADDER. 
Describe  the  bladder. 

The  bladder  lies  in  the  pelvic  cavity  behind  the  pubes,  in  front  of  the 
rectum  (vagina  and  uterus  coming  between  in  the  female).  It  is  a  mus- 
culo-membranous  bag,  and  measures,  when  moderately  distended,  5  inches 
in  length  and  3  in  width,  and  holds  about  a  pint, 

How  is  the  bladder  divided  ? 

It  is  divided  into  a  summit,  superior  surface,  base,  inferior  surface, 
and  sides. 

The  summit^  looking  forward,  is  connected  to  the  umbilicus  by  the 
urachus  centrally  and  the  obliterated  hypogastric  arteries  laterally. 

The  superior  surface  extends  from  the  summit  to  just  above  the  bot- 
tom of  the  recto-vesical  pouch.     It  is  entirely  covered  by  peritoneum. 

The  hase  extends  from  the  superior  surface  to  the  prostate  gland.  It 
is  triangular  in  shape,  with  the  apex  at  the  prostate,  and  is  bounded 
laterally  by  the  vasa  deferentia  and  vesiculae  seminales.  It  has  perito- 
neal covering  only  for  a  small  distance  just  above  the  recto-vesical  pouch. 

The  inferior  (or  pubic)  surface  extends  from  the  prostate  gland  to  the 
summit,  and  rests  on  the  triangular  ligament,  posterior  surface  of  body 
of  pubes,  and  lower  part  of  anterior  abdominal  wall. 

The  sides  are  in  apposition  with  the  recto-vesical  fascia  and  obturator 
internus  muscle. 

When  empty  the  bladder  collapses  into  the  pelvis,  and  in  section  pre- 
sents a  triangular  outline  with  the  apex  toward  the  symphysis. 

What  are  the  relations  of  the  bladder  ? 

Above. 
Abdom.  wall. 
Small  intestines. 

Front  Behind. 

Triangular  lig.  Peritoneum. 

Symp.  pubis.  Rectum. 

Abdom.  wall.  Uterus  (female). 

Pre-vesical  space  of  Retzius  (when  distended).        Small  intestines. 
Prostatic  plexus. 

Sides. 

Hypogastric  artery. 

Ureter,  obturator  internus. 

Vas  deferens,  recto-vesical  fascia. 

Base. 

Rectum  (cervix  uteri  fenaale). 
Vesiculae  seminales  (vagina  female). 
Vas  deferens. 
Prostate. 


THE   PERITONEUM.  339 

Name  the  ligaments  of  the  bladder. 

They  are  divided  into  true  ligaments,  or  those  formed  by  the  recto- 
vesical fascia,  and  in  addition  the  urachus ;  and  the  false  ones,  or  those 
formed  of  peritoneum. 

The  true  ligaments  include  the  two  anterior  or  pubo-prostatic  and  the 
two  lateral.  The  former  run  between  the  bladder  and  prostate;  the 
latter  between  the  bladder  and  sides  of  the  pelvis. 

The  false  ligaments  are  a  superior,  from  summit  of  bladder  to  navel, 
two  lateral,  to  the  iliac  fossae,  and  two  posterior.  These  latter  run  be- 
tween the  rectum  and  bladder  (uterus  and  bladder  in  the  female).  They 
contain  the  ureters.  The  hypogastric  arteries  lie  between  each  lateral 
ligament  and  the  corresponding  posterior  hgament.  The  bladder  has  a 
serous  or  peritoneal  coat,  a  muscular  coat  of  three  layers,  a  submucous 
areolar  coat,  and  a  mucous  coat. 

Describe  the  interior  of  the  bladder. 

The  mucous  membrane  is  loosely  attached  except  over  the  trigone. 
This  is  a  triangular  area  whose  apex  corresponds  to  the  urethral  opening, 
and  whose  base  extends  between  the  orifices  of  the  ureters,  indicated  by 
a  curved  elevation  due  to  a  muscular  band.  Extending  from  the  open- 
ing of  the  urethra  is  another  elevation  due  to  submucous  thickening,  the 
uvula  vesicce.     In  the  female  this  is  indistinct  and  the  trigone  is  small. 

THE  PERITONEUM. 
What  is  the  peritoneum? 

The  peritoneum  is  a  closed  serous  sac  which  invests  more  or  less  com- 
pletely the  contents  of  the  abdominal  and  pelvic  cavities,  sending  in 
processes  or  diverticula  between  the  adjacent  viscera.  These  processes 
are  attached  to  the  surfaces  of  the  viscera,  forming  their  investment, 
and  serving  also  to  separate  and  allow  a  free  movement  between  them 
without  friction.  Moreover,  they  confine  the  viscera  in  their  proper  rela- 
tive positions. 

The  walls  of  the  peritoneum  are  very  thin,  the  attached  surfaces  being 
rough ;  the  free,  smooth  and  moist  and  covered  with  a  layer  of  endothe- 
lium. That  part  which  is  attached  to  the  inner  surface  of  the  abdominal 
walls  is  called  the  parietal  layer,  while  that  investing  the  viscera  consti- 
tutes the  visceral  layer. 

Describe  the  general  arrangement  of  the  peritoneum. 

Starting  from  the  anterior  abdominal  wall,  the  peritoneum  passes 
around  on  the  right  side  to  completely  invest  the  lower  part  of  the  caecum 
and  the  vermiform  appendix,  but  only  partially  (?)  investing  the  rest  of 
the  caecum,  covering  its  front  and  sides,  the  back  part  being  very  often 
uncovered.  It  partially  invests  the  entire  ascending  colon  in  a  similar 
manner.     Quite  often,  however,  the  back  part  of  the  caecum  is  also 


340  THE   UEINARY  ORGANS   AND   PERITONEUM. 

covered  by  the  peritoneum,  which  thus  forms  a  mesocaecum.  It  now 
covers  the  lower  part  of  the  front  of  the  right  kidney  and  the  front  of 
the  third  portion  of  the  duodenum,  passes  thence  to  the  spine,  and, 
forming  the  right  side  of  the  mesentery,  invests  the  jejunum  and  ileum, 
and  returns,  as  the  left  layer  of  the  mesentery,  to  the  spine,  thus  com- 
pleting the  structure.  The  peritoneum  now  crosses  the  lower  part  of 
the  left  kidney,  invests  the  descending  colon  in  a  manner  similar  to  that 
on  the  right  side,  forms  a  long  sigmoid  mesocolon,  and  returns  to  the 
front  of  the  abdomen. 

Starting  from  the  same  place,  we  may  trace  the  peritoneum  downward 
to  completely  invest  the  rectum  in  its  upper  part  and  partially  invest  it 
below,  at  first  covering  it  in  front,  and  laterally  lower  down,  only  in 
front,  and  lastly  leaving  the  gut  altogether.  It  is  then  reflected  on  to 
the  base  and  upper  part  of  the  bladder  in  the  male,  forming  the  recto- 
vesical pouch.  This  pouch  presents  on  each  side  a  fold,  the  plica  semi- 
lunaris. From  the  apex  of  the  bladder  it  ascends,  investing  tlie  urachus 
and  obliterated  hypogastric  artery  on  each  side.  In  the  female  it  passes 
from  the  rectum  to  the  upper  part  of  the  vagina,  forming  the  pouch  of 
Douglas,  which  presents  plicae  semilunares  similar  to  those  found  in  the 
recto-vesical  pouch  in  the  male.  It  then  covers  both  surfaces  of  the 
uterus,  and  forms  the  broad  ligaments,  investing  the  Fallopian  tubes  to 
the  fimbriated  ends,  where  it  becomes  continuous  with  their  mucous  mem- 
brane. 

Above,  the  peritoneum  runs  on  the  under  surface  of  the  diaphragm  as 
far  back  as  the  oesophageal  opening,  and  meets  the  process  ot  the  lesser 
sacj  which  lies  on  the  posterior  surface  of  the  liver.  It  also  forms  the 
coronary,  lateral,  and  falciform  ligaments.  At  the  anterior  border  of 
the  liver  it  is  reflected  on  to  the  under  surface,  covers  the  quadratic 
lobe,  and  at  the  transverse  fissure  it  meets  the  posterior  layer  of  the 
lesser  or  gastro-hepatic  omentum  from  the  lesser  sac,  and  passes  with  it 
to  the  lesser  curvature  of  the  stomach  as  the  anterior  layer,  thus  com- 
pleting the  omentum.  From  the  quadrate  lobe  it  invests  the  gall-blad- 
der to  a  variable  degree,  the  under  surface  of  the  right  lobe  of  the  liver, 
the  front  of  the  second  portion  of  the  duodenum,  and  the  upper  part  of 
the  right  kidney,  forming  here  the  fold  known  as  the  hepato-renal  Hga- 
ment.  Lastly,  it  invests  the  hepatic  flexure  of  the  colon,  and  proceeds 
to  the  right  colon  in  the  manner  previously  described. 

To  the  left  of  the  longitudinal  fissure  of  the  liver  it  covers  the  entire 
under  and  upper  surface  of  the  left  lobe  of  the  liver,  forming  the  left 
lateral  ligament.  Tracing  to  the  left  the  anterior  layer  of  the  lesser 
omentum,  the  peritoneum  covers  the  front  and  left  side  of  the  oesophagus 
and  left  end  of  the  stomach,  passing  thence  to  invest  the  spleen,  and 
forming  the  anterior  layer  of  the  gastro-splenic  omentum.  Passing  from 
the  diaphragm  to  the  stomach  to  the  left  of  the  gullet,  there  is  formed  the 
gastro- phrenic  fold  or  ligament,  and  between  the  diaphragm  and  splenic 
flexure  the  costo-colic  ligament. 


THE   PERITONEUM.  341 

Describe  the  lesser  sac  of  the  peritoneum. 

This  is  a  process  of  the  peritoneum  which  Hnes  the  space  bounded  by 
the  posterior  surfaces  of  the  Uver  and  stomach  and  the  upper  surface  of 
the  transverse  colon.  It  communicates  with  the  greater  sac  by  means  of 
the  foramen  of  Winslow,  which  is  bounded  in  front  by  the  lesser  omen- 
tum, with  the  portal  vein  and  hepatic  artery  and  duct  between  its  layers, 
behind  by  the  vena  cava  inferior,  above  by  the  lobus  caudatus,  below  by 
the  duodenum.  From  this  point  the  lesser  sac  lines  the  posterior  abdom- 
inal wall,  and  adheres  to  the  back  of  the  greater  sac  except  where  the 
stomach  comes  between.  Above  it  passes  behind  the  liver,  between  the 
Spigelian  lobule  and  the  back  part  of  the  diaphragm,  to  meet  the  pro- 
cess from  the  greater  sac  already  described.  Here  it  is  attached  to  the 
transverse  fissure  and  the  fissure  of  the  ductus  venosus,  covering  the 
oesophagus  behind  and  on  the  right.  At  the  transverse  fissure  it  passes 
to  the  lesser  curvature  of  the  stomach,  forming  the  posterior  layer  of  the 
lesser  or  gastro-hepatic  omentum,  the  anterior  layer  coming  from  the 
greater  sac.  It  then  invests  the  back  of  the  stomach,  and  descends 
from  the  great  curvature  in  front  of  the  transverse  colon  and  small  intes- 
tine to  a  greater  or  less  extent.  Turning  upon  itself,  it  ascends,  thus 
forming  the  internal  layers  of  the  great  omentum,  as  far  as  the  trans- 
verse colon,  whose  upper  surface  it  invests,  and  passes  thence  to  the 
spine,  thus  forming  the  upper  layer  of  the  transverse  mesocolon.  It 
now  passes  upward  over  the  front  of  the  pancreas,  coeliac  axis  and  its 
branches,  upper  part  of  left  kidney,  the  left  suprarenal  capsule,  and  that 
part  of  the  diaphragm  between  the  aortic  and  cava!  openings,  and  is 
continuous  with  that  part  of  the  lesser  sac  lining  the  space  back  of  the 
liver,  already  described.  Traced  to  the  left  over  the  pancreas,  the  peri- 
toneum is  reflected  to  the  hilus  of  the  spleen,  and  thence  to  the  stomach, 
forming  the  posterior  layer  of  the  gastro-splenic  omentum.  Traced  to 
the  right,  it  is  reflected  from  the  extreme  end  of  the  pancreas  on  to  the 
back  of  the  first  portion  of  the  duodenum,  and  becomes  continuous  with 
that  covering  the  posterior  surface  of  the  stomach. 

Describe  the  formation  of  the  great  omentum. 

The  anterior  layer  of  the  lesser  omentum  invests  the  front  of  the 
stomach  to  the  greater  curvature,  from  which  it  descends  in  front  of  and 
with  the  posterior  layer,  and  thus  in  front  of  the  transverse  colon  and 
small  intestine,  to  a  variable  degree.  Still  outside  of  the  posterior  layer 
(from  the  lesser  sac),  it  is  reflected,  in  a  manner  similar  to  that  layer, 
upon  itself,  and,  ascending  with  it,  completes  the  great  omentum.  Those 
layers,  therefore,  of  the  great  omentum  which  are  contributed  by  the 
lesser  sac  are  continued  within  those  from  the  greater  sac.  At  the  trans- 
verse colon  the  layers  of  the  greater  omentum  separate  and  enclose  the 
gut,  meeting  behind  and  completing  the  transverse  mesocolon,  which 
extends  to  the  lower  border  of  the  pancreas.  Here  the  inferior  layer 
(from  the  greater  sac)  runs  down  along  the  posterior  abdominal  wall  and 


342  ORGANS   OF   REPRODUCTION   (mALE). 

blends  with  the  mesentery  as  described,  and  the  superior  layer  (from  the 
lesser  sac)  proceeds  as  already  mentioned. 

ORGANS  OP  REPRODUCTION  (MALE). 

THE   PROSTATE   GLAND. 

The  prostate  gland  surrounds  the  so-called  neck  of  the  bladder  and 
the  commencement  of  the  urethra.  It  rests  against  the  rectum  behind, 
and  lies  on  the  subpubic  fascia  (posterior  layer  of  triangular  ligament). 
It  resembles  a  chestnut  in  form,  and  measures  transversely  IJ  inches,  from 
base  to  apex  1 J  inches,  and  nearly  1  inch  in  thickness,  its  weight  being  6 
drachms.  The  hase  looks  toward  the  neck  of  the  bladder,  its  apex  touches 
the  deep  perineal  fascia  (triangular  hgament),  the  posterior  surface  is 
joined  to  the  rectum  by  areolar  tissue,  and  its  pubic  surface^  grooved 
longitudinally,  lies  J  inch  from  the  pubic  symphysis.  It  is  supported  in 
-its  position  by  the  pubo-prostatic  ligaments,  posterior  layer  of  the  deep 
perineal  fascia,  and  the  front  of  each  levator  ani  (the  levator  prostatas). 

The  prostate  consists  of  two  lateral  lobes  and  a  middle  lobe.  The 
lateral  lobes  are  separated  behind  by  a  deep  notch,  and  are  continuous  in 
front  of  the  urethra.  The  middle  is  smaller,  lying  between  the  lateral 
lobes,  the  bladder,  and  the  adjacent  portion  of  the  urethra. 

The  urethra  and  common  seminal  ducts  pierce  the  prostate.  The  gland 
has  a  dense,  firm,  fibrous  capsule,  which  is  derived  from  the  recto-vesical 
fascia  and  the  posterior  layer  of  the  triangular  ligament,  and  it  consists 
of  glandular  and  muscular  tissue. 

THE  PENIS. 
Describe  the  penis. 

The  penis  consists  of  three  cylindrical  masses  of  erectile  tissue  united 
together,  the  two  upper  of  which,  lying  side  by  side  and  called  the 
corpora  cavernosa,  form  the  chief  bulk  of  the  organ,  and  the  lower,  the 
corpus  spongiosum,  contains  part  of  the  urethra.  The  root  is  attached 
to  the  pubic  rami  by  the  crura,  and  to  the  symphysis  by  the  suspensory 
ligament.  The  body  is  cylindrical  when  flaccid,  triangular  with  rounded 
border  and  sides  when  erect,  the  upper  side  being  the  dorsum.  It  is 
covered  by  a  very  thin  skin,  which  is  dark  in  color  and  devoid  of  adipose 
tissue,  being  loosely  connected  to  the  organ.  This  skin  folds  upon  itself 
in  front  to  form  the  prepuce,  the  under  layer  of  which  joins  the  cervix 
and  becomes  very  like  a  mucous  membrane,  covering  the  glans  and  blend- 
ing into  the  mucous  membrane  of  the  urethra  at  the  meatus.  Around 
the  cervix  and  corona  glandis  are  small  glands,  the  glanduloe  Tysoni 
odoriferse.  The  glans  is  conical  and  points  anteriorly,  its  summit  pre- 
senting a  vertical  slit,  the  meatus  nrinarivs,  from  the  lower  part  of 
which  a  fold  of  mucous  membrane  runs  back  to  join  the  prepuce,  and 
is  called  the  frcenum  proeputii.     The  base  of  the  glans  projects  at  its 


THE   MALE   URETHRA.  343 

circumference,  forming  the  corona  glandis^  behind  which  is  a  constriction, 
the  cervix. 

The  corpora  cavernosa  are  closely  connected  for  the  anterior  three- 
fourths,  being  flattened  mesially,  while  behind  they  separate,  and, 
enlarging  at  first  to  form  the  bulb  of  the  corpus  cavernosum,  gradually 
taper,  and  under  the  name  of  crura  penis  are  attached  to  the  rami  of 
the  pubes  and  ischium.  In  front  they  form  a  single  blunt  extremity 
which  is  joined  by  fibrous  tissue  to  the  base  of  the  glans.  Below  them 
is  a  groove  for  the  corpus  spongiosum,  and  above  one  for  the  dorsal  vein 
of  the  penis. 

The  fibrous  envelope  is  composed  of  longitudinal  fibres  common  to 
both  corpora,  and  circular  fibres  which  are  internal  and  belong  to  one 
corpus  only.  Mesially,  where  the  circular  fibres  of  both  sides  meet,  they 
unite  to  form  a  septum.  This  septum  is  thick  and  complete  behind,  but 
in  front  many  vertical  slits  allow  of  communication  between  the  two 
bodies,  and  have  given  to  the  septum  the  name  septum  pectiniforme. 
From  the  inner  surface  of  this  envelope  numerous  fibrous  trabeculae 
pass  in  all  directions.  These  trabeculae  support  and  enclose  the  arterial 
branches,  which  form  a  capillary  network  opening  directly  into  the  cav- 
ernous spaces,  some  of  them  forming  convoluted  vessels,  the  helicine 
arteries,  which  project  into  the  trabecular  spaces.  The  blood  is  returned 
by  the  dorsal  vein,  prostatic  plexus,  and  pudendal  veins. 

The  corpus  spongiosum  commences  behind,  between  the  two  crura, 
and  in  front  of  the  deep  perineal  fascia,  as  the  hulh^  and  in  front  ex- 
pands to  form  the  glans.  The  bulb  receives  an  investment  from  the 
anterior  layer  of  the  deep  perineal  fascia  and  is  surrounded  by  the  accel- 
erator urinae  muscles.  The  urethra  runs  through  the  upper  part  of  the 
corpus  spongiosum,  surrounded  by  a  layer  of  erectile  tissue,  the  part 
within  the  bulb  being  called  the  bulbous  portion  of  the  urethra.  The 
fibrous  envelope  is  white,  thinner  than  that  of  the  corpora  cavernosa,  and 
encloses  a  similar  trabecular  structure.  Just  beneath  it,  forming  part 
of  the  outer  coat,  is  a  layer  of  muscular  fibres,  and  a  second  muscular 
layer  lies  beneath  the  urethral  mucous  membrane. 

THE  MALE   URETHRA. 
Describe  the  urethra,  and  give  its  three  divisions. 

The  male  urethra  extends  from  the  neck  of  the  bladder  to  the  end  of 
the  penis,  is  about  8i  inches  long,  and  is  lined  throughout  by  mucous 
membrane  supported  by  a  submucous  tissue  and  connected  by  it  with  the 
subjacent  tissues  in  its  three  parts — ;viz.  the  prostatic,  membranous,  and 
spongy.  Part  of  the  submucous  tissue  is  composed  of  a  longitudinal 
muscular  layer  internally  and  a  circular  externally. 

The  prostatic  portion  is  the  widest  part  of  the  canal,  and  traverses 
the  prostate  gland,  being  about  IJ  inches  long,  widest  at  the  middle,  and 
lying  above  the  middle  lobe.  It  is  very  dilatable.  On  its  floor  is  a  slight 
elevation  at  the  back  part,  which  passes  back  to  the  uvula  vesicae,  and 


344  ORGANS   OF   REPRODUCTION   (mALE). 

is  placed  in  the  median  line,  measuring  f  inch  long  and  about  i  inch  at 
its  maximum  height.  This  ridge  has  been  variously  named  the  crista 
urethras,  coUicnhis  semlnalis^  verumontarmm^  and  caput  gaUiiiaginis. 
On  each  side  of  it  is  a  groove,  the  prostatic  sinus,  the  floor  of  which 
presents  the  orifices  af  the  numerous  prostatic  ducts. 

In  the  fore  part  of  the  verumontanum  is  a  depression,  which  leads 
into  the  simis  pocfularis  or  uterus  mascuUnus,  upon  or  within  the  margins 
of  which  are  the  ^orifices  of  the  ejaculatory  ducts.  This  sinus  forms  a 
cul-de-sac  running'in  the  verumontanum  and  beneath  the  middle  lobe  of 
the.'^'f'ostate.'     '".    '' 

The 'membranous  portion  Hes  between  the  apex  of  the  prostate 
and  the  bulb  of  the  corpus  spongiosum,  and  is  the  narrowest  part  of 
the  canal.  It  is  f  inch  long.  It  pierces,  lies  between,  and  is  invested 
by  the  anterior  and  posterior  layers  of  the  deep  perineal  fascia,  and  is 
surrounded  by  the  compressor  urethras,  one  of  Cowper's  glands  lying 
on  each  side. 

Cowpers  glands  are  yellowish,  lobulated  bodies,  of  the  size  of  a  pea, 
lying  between  the  two  layers  of  the  deep  perineal  fascia,  behind  the  mem- 
branous urethra,  and  between  the  arteries  of  the  bulb  above  and  the  trans- 
verse fibres  of  the  compressor  urethras  below.  The  lobules  are  made  up 
of  acini  and  joined  together  by  fibrous  tissue.  The  ducts  from  the  lob- 
ules unite  outside  the  gland  into  a  common  duct,  which  runs  forward 
beneath  the  mucous  membrane  for  about  an  inch  and  opens  on  the  floor 
of  the  bulbous  portion  of  the  urethra. 

The  spongy  portion  of  the  urethra  is  enclosed  by  the  corpus  spon- 
giosum, and  is  about  6 J  inches  long.  The  bulbous  portion^  or  sinu^^  is 
dilated,  but  beyond  the  bulb  the  urethra  is  of  uniform  calibre  as  far  as 
the  glans,  in  which  it  is  again  dilated,  forming  here  the  fossa  navicularis, 
and  its  long  axis  becomes  vertical  instead  of  transverse.  At  the  meatus 
it  is  much  contracted. 

The  mucous  membrane  presents  the  orifices  of  many  small  racemose 
glands  (glands  of  Littre)  and  of  many  lacunae.  One  of  these  latter,  in 
the  upper  part  of  the  fossa  navicularis,  is  considerably  dilated,  and  is 
called  the  lacuna  magna. 


THE  TESTES. 
Describe  the  spermatic  cord. 

The  testicles  are  two  glandular  organs  suspended  in  the  scrotum  by 
the  spermatic  cord. 

The  spermatic  cord  extends  from  the  internal  ring  to  the  back  of  the 
testis.  Its  various  parts  are  connected  together  by  areolar  tissue,  and 
are  invested  by  the  various  processes  of  the  fascia,  which  descends  with 
the  testicle.  In  its  course  through  the  inguinal  canal  it  lies  at  first 
between  the  internal  oblique  and  the  fascia  transversalis,  the  former 
at  times  arching  over  it ;  then  between  the  aponeurosis  of  the  external 


PLATE  XXIX. 

Fig.  '[.—To  face  page 


Cowpefs  Gland.' 


Orifices  of  ^wc<s^^^U[|; 
of  Cowper's  Glands. 


Meatus. 
The  Bladder  and  Urethra,  laid  open,  seen  from  above. 


PLATE  XXX. 

Fig.  1. —To  face  page  ^ 

Tunica  Vaginalis. 
Tunica  Albuginea. 
Its  Septa. 


c 

-Q 

-l-J 

S 

^ 

ft 

o 

<x> 

•^ 

rJ3 

QD 

-1-3 

^ 

o 

CD 

^J 

^ 

fi 

Fig.  2.— To  face  page  347. 


Eight  Ejaculatory 
duct. 


i 


>1 
■s  a 


^.1 
II 


THE   TESTES.  345 

oblique  and  the  conjoined  tendon ;   and  Poupart's  ligament  is  below. 
The  left  cord  is  the  longer. 

Of  what  is  the  spermatic  cord  composed  ? 

It  is  composed  of  the  spermatic  artery,  artery  of  the  vas  deferens,  and 
cremasteric  artery,  the  spermatic  veins  from  the  back  of  the  testis,  which 
receive  the  veins  from  the  epididymis  to  form  the  pampiniform  plexus, 
a  number  of  large  lymphatics,  and  the  spermatic  plexus  of  the  sympa- 
thetic, together  with  the  vas  deferens,  the  layers  of  fascia  which  cover 
the  testicle,  and  the  remains  of  the  peritoneal  testicular  process. 

What  are  the  boundaries  of  the  inguinal  canal  ? 

The  inguinal  canal  is  bounded  behind  by  the  fascia  transversalis  and 
the  conjoined  tendon  ;  in  front  by  the  transversalis  and  internal  oblique 
above,  and  tlie  external  oblique  aponeurosis  below ;  its  floor  is  formed  by 
the  curving  back  of  Poupart's  ligament ;  its  roof  by  the  arched  fibres  of 
the  internal  oblique  in  apposition  with  the  aponeurosis  of  the  external 
obUque. 

Give  the  coverings  of  the  testicle. 

The  testicle  is  covered  from  without  inward  by  the  following  structures : 
the  scrotum,  composed  of  skin  and  dartos;  the  intercolumnar  or  ex- 
ternal spermatic  fascia;  cremasteric  fascia;  infundibuliform  fascia,  or 
internal  spermatic  fascia ;  tunica  vaginalis. 

What  is  the  scrotum? 

The  scrotum  is  a  pocket  which  contains  the  testicles  and  part  of  the 
spermatic  cords,  and  is  marked  superficially  by  a  median  ridge,  the  raphe, 
which  runs  from  the  penis  along  the  scrotum  and  perineum  to  the  anus. 
The  scrotum  consists  of  a  layer  of  skin  and  the  dartos. 

The  sJcm  is  thin  and  dark,  and  presents  folds  or  rugae,  is  covered  with 
hairs  thinly  scattered,  and  is  furnished  with  sebaceous  glands. 

The  dartos  is  a  thin  contractile  tunic,  of  a  reddish  color,  continuous 
with  the  superficial  fascia  of  the  groin  and  perineum  ;  it  is  very  vascular, 
and  is  composed  of  loose  areolar  tissue  and  unstriped  muscle.  It  sends 
in  a  partition,  the  septum  scroti,  which  separates  the  two  testes,  and  is 
attached  to  the  under  surface  of  the  penis  and  to  the  raphe. 

Give  the  fasciae  within  the  scrotum. 

The  intercolumnar  fascia,  separated  by  loose  areolar  tissue  from  the 
dartos,  is  attached  to  and  descends  from  the  margins  of  the  pillars  of 
the  external  ring. 

The  cremasteric  fascia  consists  of  scattered  muscular  loops  or  bundles 
(crem aster  muscle),  connected  together  by  areolar  tissue,  the  former 
being  continuous  with  the  lower  border  of  the  internal  oblique. 

The  infundibuliform  fascia  is  continuous  above  with  the  fascia  trans- 


346  ORGANS   OF   REPRODUCTION   (mALE). 

versalis  and  the  subserous  areolar  tissue  of  the  peritoneum.     These  two 
together,  the  latter  being  underneath,  form  the  fascia  propria.     It  in- 
vests the  surface  of  the  cord  and  sends  in  septa  between  its  component 
parts. 
The  tunica  vaginalis  (see  Testicle  proper). 

Describe  the  testicle  proper  and  epididymis. 

^  Each  testicle  is  ovoid,  flattened  from  side  to  side,  and  suspended  ob- 
liquely (the  left  being  somewhat  the  lower),  its  upper  end  being  directed 
forward,  outward,  and  upward,  the  lower  in  the  opposite  direction. 
•Each  is  IJ  inches  long,  \\  inches  wide,  and  less  than  1  inch  thick,  and 
weighs  i  to  1  ounce. 

The  front,  sides,  and  both  ends  of  the  testis  are  free,  smooth,  and 
covered  by  the  tunica  vaginalis.  At  the  posterior  border  the  vessels  and 
nerves  enter  and  emerge,  and  to  this  border,  as  well  as  to  the  outer  sur- 
face, is  attached  the  epididymis. 

The  epididymis  is'  a  long,  narrow  structure,  made  up  of  a  hody^  a 
head  or  globus  major^  and  a  tail  or  globus  minor. 

The  globus  major  is  large,  and  joined  to  the  upper  end  of  the  testicle 
by  the  efl'erent  ducts ;  the  minor  is  small  and  pointed,  and  is  joined  to 
the  lower  end  of  the  testicle  by  a  reflection  of  the  tunica  vaginalis  and 
some  cellular  tissue.  The  convex  surface  and  anterior  border  of  the 
epididymis  are  free  and  covered  by  the  tunica  vaginalis,  as  is  also  the 
concave  or  attached  surface  (except  at  the  ends),  the  serous  membrane 
here  forming  the  digital  fossa.  On  the  front  oi  the  globus  major  are 
one  or  more  small  pedunculated  bodies  called  the  hydatids  of  Morgagni, 
believed  to  be  the  remains  of  Miiller's  duct.  The  epididymis  is  a  con- 
voluted canal  whose  lumen  is  continuous  with  that  of  the  vas  deferens. 

The  tunica  vaginalis  is  a  closed  serous  sac,  and  consists  of  a  vis- 
ceral layer  and  a  parietal  layer. 

The  visceral  layer  adheres  to  the  outer  surface  of  the  tunica  albuginea, 
suiTounding  the  testis  and  epididymis,  and  joining  them  together  by  a 
fold.     It  forms  between  them  the  pouch  known  as  the  digital  fossa. 

The  parietal  layer  is  reflected  on  to  the  inner  surface  of  the  scrotum 
at  the  posterior  border  of  the  testicle. 

The  tunica  albuginea  is  the  fibrous  coat  which  surrounds  the  soft 
substance  of  the  testis  and  is  reflected  at  the  posterior  border  into  its  in- 
terior, forming  a  sort  of  septum,  the  corpus  Highmori  or  mediastimmi 
testis.  This  septum,  wider  above  than  below,  extends  from  the  upper 
nearly  to  the  lower  end  of  the  gland,  and  sends  off"  numerous  trabeculae 
which  join  the  inner  surface  of  the  tunica  albuginea.  These  divide  the 
organ  incompletely  into  lobules.  The  tunica  vascuJosa  (pia  mater  testis) 
is  a  vascular  plexus  supported  by  areolar  tissue  which  covers  the  inner 
surface  of  the  tunica  albuginea  and  its  trabeculae. 

The  gland  substance  consists  of  seminiferous  tuhules,  which  are 
contained  within  the  lobules  above  mentioned,  each  lobule  containing  two 


THE   TESTES.  347 

or  three  seminiferous  tubules.  Each  of  these  latter  is  lined  by  several 
layers  of  epithelial  cells,  from  which,  by  a  process  of  division  (karyoki- 
nesis),  are  finally  developed  the  spermatozoa. 

The  lobules  are  conical,  their  bases  being  turned  toward  the  circum- 
ference, their  apices  toward  the  mediastinum.  In  the  latter  situation 
the  tubules  become  straighter,  and  unite  to  form  twenty  to  thirty  large 
ducts,  the  tuhuli  recti  These  tuhuli  recti  open  into  a  vascular  network, 
the  rete  testis,  which  lies  in  the  substance  of  the  mediastinum,  and  from 
this  issue  twelve  to  twenty  vasa  efferentia,  which  pierce  the  tunica  albu- 
ginea  and  enter  the  globus  major  of  the  epididymis,  where  they  now 
become  tortuous  and  form  conical  masses,  the  cojii  vasculosL 

Describe  the  vas  deferens,  the  vesiculse  seminales,  and  the  ejac- 
ulatory  ducts. 

The  vas  deferens,  the  continuation  of  the  epididymis,  is  the  excre- 
tory duct  of  the  testicle.  From  the  globus  minor  it  runs  along  the  inner 
side  of  the  epididymis  and  back  of  the  testis,  and  in  the  spermatic  cord 
to  the  internal  ring :  here  it  descends,  crossing  the  external  iliac  vessels, 
and  curving  around  the  outer  side  of  the  deep  epigastric  artery.  It  now 
passes  beneath  the  peritoneum  to  the  side  of  the  bladder,  and  runs  down- 
ward and  backward  to  its  base,  internal  to  the  ureter  and  across  the  ob- 
literated hypogastric  artery.  At  the  base  of  the  bladder  it  lies  between 
it  and  the  rectum,  internal  to  the  seminal  vesicle,  the  duct  of  which  it 
joins  (close  to  the  base  of  the  prostate)  after  having  enlarged  and  again 
narrowed,  forming  with  it  the  ejaculatory  duct.  Its  length  is  about  2 
feet  and  its  diameter  about  ^  inch.  It  has  an  external  areolar  coat,  a 
middle  muscular  coat  of  two  layers,  longitudinal  and  circular,  and  an 
internal  mucous  coat  covered  with  columnar  epithelium. 

The  vesiculse  seminales,  conical  in  form,  the  wider  end  looking 
backward,  lie  between  the  rectum  and  the  base  of  the  bladder,  and  are 
the  reservoirs  for  the  semen.  They  are  2  inches  long  and  i  inch  wide. 
In  front  they  converge,  and  each  joins  the  corresponding  vas  deferens  at 
the  base  of  the  prostate  to  form  the  ejaculatory  duct.  The  vesicle  is  a 
single  tube  4  to  6  inches  long,  coiled  up  and  giving  ofi*  diverticula.  It 
ends  behind  in  a  blind  extremity,  and  is  2  inches  long  in  its  natural  con- 
dition. 

Each  ejaculatory  duct  is  f  inch  long,  and  runs  one  on  each  side, 
forward  and  upward  within  the  prostate,  between  its  middle  and  lateral 
lobes,  and  along  the  walls  of  the  sinus  pocularis,  close  to  the  opening 
of  which  they  empty.  Each  has  an  areolar,  a  muscular,  and  a  mucous 
coat. 

The  semen  is  a  whitish  fluid  composed  of  liquor  seminis,  seminal 

Granules,  and  spermatozoa.  The  granules  are  ^oo  inch  in  diameter, 
'he  spermatozoa  consist  of  a  head,  formerly  the  nucleus  of  a  spermato- 
blast, a  body,  and  a  tail.  The  spermatoblasts  constitute  one  of  the 
layers  of  epithelial  cells  lining  the  seminiferous  tubules. 


348  ORGANS   OF   REPRODUCTION   (fEMALE). 

ORGANS  OF  REPRODUOTION  (FEMALE). 
External. 

THE  VULVA. 
Describe  the  vulva. 

The  term  vulva  or  pudendum  includes  the  mons  veneris  and  labia,  the 
nymphae  and  clitoris,  the  hymen  or  its  remains,  the  meatus  urinarius, 
and  the  vaginal  orifice. 

Describe  these  various  parts. 

The  mons  veneris  is  a  fatty  cushion  covering  the  front  of  the  pubes, 
and  after  puberty  is  plentifully  supplied  with  hairs.  Below,  it  divides  into 
the  two  labia  majora,  which,  diminishing  in  size  as  they  pass  downward 
and  backward,  unite  an  inch  in  front  of  the  anus.  The  two  extremities 
are  joined,  and  form  the  anterior  and  posterior  commissures.  Between 
the  latter  and  the  anus  is  the  perineum,  and  just  within  the  posterior 
commissure  is  a  transverse  fold,  the  fraenulum  pudendi  or  fourchette. 
Between  this  fold  and  the  posterior  commissure  is  a  triangular  space,  the 
fossa  navicularis. 

The  nymphce^  or  labia  minora,  smaller  than  the  above,  run  from  the 
middle  of  the  labia  majora  upward  to  the  clitoris,  each  dividing  into  two 
folds,  the  upper  pair  of  which  join  to  form  a  prepuce  for  that  organ, 
and  the  lower  two  to  form  its  fraenum.  They  are  continuous  externally 
with  the  labia  majora,  internally  with  the  vagina.  The  mons  veneris  is 
composed  interiorly  of  fatty  and  fibrous  tissue ;  the  labia,  of  areolar  fatty 
and  dartoid  tissue,  with  vessels  and  nerves ;  the  nymphae,  of  a  plexus 
of  vessels  covered  by  mucous  membrane. 

The  clitoris  is  the  analogue  of  the  penis,  consisting  like  it  of  two 
corpora  cavernosa  united  by  a  septum  pectiniforme,  and  prolonged  behind 
into  two  crura  attached  to  the  pubic  and  ischial  rami.  It  also  has  a  sus- 
pensory ligament  and  a  glans  enclosed  by  the  nymphae.  Two  erectores 
clitoridis  muscles  are  attached  to  the  crura.  It  has  no  corpus  spongiosum 
nor  urethra. 

Between  the  clitoris  and  the  vagina,  bounded  on  each  side  by  the 
nymphae,  is  the  vestibule,^  a  triangular  space,  in  which,  just  above  the 
vagina,  is  the  meatus  urinarius,  1  inch  below  the  clitoris. 

The  hymen  is  a  mucous  fold  which  more  or  less  completely  occludes 
the  orificium  vaginae.  It  is  generally  semilunar  in  form,  concave  above, 
or  it  may  be  a  complete^  membrane,  perforate  or  imperforate,  or  it  may 
be  absent.     After  labor  its  remains  form  the  carunculae  myrtiformes. 

The  glands  of  Bartholin^  the  analogues  of  Cowper's  glands  in  the 
male,  are  two  yellowish  bodies  on  each  side  of  the  vaginal  opening, 
each  of  which  discharges  by  a  single  duct  between  the  hymen  and  the 
nymphae. 

On  each  side  of  the  vestible,  behind  the  nymphae,  is  a  leech-shaped 
mass,  the  hulhus  vestibidi     Each  consists  of  a  venous  plexus  enclosed 


THE   UKETHRA. — THE   UTERUS.  349 

by  a  fibrous  capsule,  and  is  about  1  inch  long.     In  front  of  these,  and 
connecting  them  with  the  vessels  of  the  clitoris,  is  a  small  venous  plexus, 
.  the  pars  intermedia  of  Kobelt. 

THE  URETHRA. 
Describe  the  urethra. 

The  female  urethra  is  a  mucous  canal,  H  inches  long,  running  down- 
ward and  forward  in  the  anterior  vaginal  wall  from  the  neck  of  the 
bladder  to  the  meatus.  As  in  the  male,  it  pierces  the  triangular  liga- 
ment, and  is  surrounded  by  the  compressor  urethrse  muscle.  It  consists 
of  a  muscular,  a  mucous,  and,  between  them,  an  erectile,  coat.  It  is 
supplied  with  numerous  glands,,  and  just  within  the  meatus  near  the 
floor  are  two  ducts  which  extend  upward  for  about  f  inch.  These  are 
called  Skene's  tubules. 

THE  VAGINA. 
Describe  the  vagina. 

The  vagina  extends  from  the  vulva  to^  the  uterus,  lying  behind  the 
bladder  and  in  front  of  the  rectum,  and  is  about  4  inches  long  on  its 
anterior  wall,  5  to  5  J  on  its  posterior,  and  is  directed  from  the  uterus 
downward  and  forward. 

Above,  it  embraces  the  cervix  uteri,  and  its  walls  are  flattened  from 
before  backward.  It  is  narrowest  at  the  introitus,  or  orificium  vaginge. 
Li  front  it  is  in  relation  with  the  urethra  and  base  of  the  bladder; 
behind  it  is  connected  with  the  anterior  wall  of  the  rectum  by  its  lower 
three-fourths,  the  cul-de-sac  of  peritoneum  (Douglas's)  separating  them 
above ;  laterally  the  broad  ligaments  are  attached  above,  and  the  leva- 
tores  ani  below,  as  well  as  the  recto-vesical  fascia.  Its  inner  surface  pre- 
sents a  mesial  ridge  or  raphe  on  the  front  and  back  walls,  the  columuse 
ru^arum,  and  from  them  on  both  sides  run  out  transverse  folds  or  rugae. 

The  vaginal  mucous  membrane  is  squamous,  with  papillae  here  and 
there.  The  submucous  coat  holds  many  large  veins  and  some  muscular 
fibres,  making  a  sort  of  erectile  tissue.  The  veins  form  a  sort  of  plexus. 
The  muscular  coat  comprises  an  internal  circular  and  an  external  longi- 
tudinal layer.  At  the  lower  part  is  the  sphincter  vaginae,  a  muscle 
composed  of  striped  fibres. 

The  internal  organs  include  the  uterus^  tubes,  and  ovaries. 

Internal. 

THE  UTERUS. 
Describe  the  uterus. 

The  uterus  or  womb  is  a  hollow  muscular  organ  lying  in  the  pelvis 
between  the  bladder  and  rectum.  In  the  virgin  it  is  pear-shaped, 
flattened  from  before  backward,  its  upper  end  looking  forward  and  up- 
ward, its  lower  downward  and  backward,  forming  an  angle  with  the 


350  ORGANS   OF   REPRODUCTION   (fEMALE). 

vagina.  Above,  it  is  invested  by  the  peritoneum,  which  covers  its  body 
before  and  behind ;  it  covers  also  the  cervix  behind,  but  in  front  the 
peritoneum  is  reflected  on  to  the  bladder  before  reaching  the  cervix.  . 
Its  upper  and  back  part  is  in  contact  with  the  small  intestine,  its  lower 
and  front  part  with  the  bladder,  the  peritoneum  separating  them.  The 
two  folds  of  peritoneum  after  investing  the  uterus  are  applied  to  each 
other  and  form  the  broad  ligaments. 

The  uterus  is  3  inches  long,  2  wide,  and  1  thick,  and  it  weighs  about  1 
ounce.  It  is  divided  into  a  body,  fundus,  and  neck.  The  fundus  is 
the  convex  part  above  the  entrance  of  the  tubes ;  the  body  is  the  part 
between  this  and  the  neck.  In  fi'ont  of  the  Fallopian  tubes,  at  the  up- 
per part  of  the  lateral  borders,  the  round  ligaments  are  attached,  and 
below  and  behind  them  are  the  ligamenta  ovarica.  The  cervix  is  the 
lower  constricted,  rounded  part,  and  around  it  is  attached  the  vagina. 
At  its  vaginal  end  is  a  transverse  opening,  the  os  uteri,  the  posterior  lip 
of  which  is  thin  and  long,  the  anterior  thick. 

Describe  the  cavity  of  the  uterus. 

The  cavity  of  the  uterus  is  small ;  that  part  within  the  body  is  tri- 
angular, flattened  antero-posteriorly,  and  presents  at  the  superior  angles 
the  openings  of  the  Fallopian  tubes ;  also,  at  its  junction  with  the  neck 
it  is  constricted  to  form  the  os  internum  or  isthmus.  The  cavity  of  the 
cervix  is  barrel-shaped  and  flattened  antero-posteriorly,  presenting  on 
each  wall  a  longitudinal  column  sending  ofi"  oblique  rugae  on  each  side ; 
hence  its  name,  arbor-vitae  uterinus. 

Give  the  structure  of  the  walls  of  the  uterus. 

The  walls  of  the  uterus  consist  of  an  outer  serous  coat  (already  de- 
scribed), an  inner  mucous,  and  an  intermediate  muscular.  The  muscular 
coat  forms  the  bulk  of  the  uterus,  and  consists  of  bundles  and  layers  of 
unstriped  fibres  which  interlace,  and  of  some  areolar  tissue  supporting 
them,  and  of  blood-vessels,  lymphatics,  and  nerves.  Three  laj^ers  are 
described — an  external  transverse  layer,  some  of  the  fibres  being  con- 
tinued on  to  the  Fallopian  tubes,  etc.  ;  a  middle  layer  of  intermixed 
longitudinal,  oblique,  and  transverse  fibres ;  and  an  internal  layer,  which 
is  circularly  arranged  at  the  cervix,  forming  the  so-called  external  and 
internal  sphincters.  This  layer  is  the  muscularis  mucosae  of  the  mucous 
membrane. 

Describe  the  mucous  membrane  of  the  uterus. 

The  mucous  membrane  of  the  body  differs  from  that  of  the  cervix. 
The  former  is  smooth,  reddish,  with  columnar  cells,  and  presents  the 
ducts  of  a  number  of  tubular  glands  which  end  by  blind,  sometimes 
forked,  extremities.  In  the  cervix  it  is  firmer,  and  presents  numerous 
saccular  and  tubular  glands  between  the  rugae  of  the  arbor  vitae,  and, 
below,  numerous  papillae.  The  glands  are  sometimes  distended  by  their 
secretion,  the  ducts  being  choked,  and  present  the  appearance  of  vesi- 


PLATE  XXXI. 

Fig.  1. — To  face  pages  349  and  350. 


Antero-posterior  (sagittal)  Section  of  the  Pelvic  Organs  of  a  Virgin : 
Ijjvagina ;  2,  uterus  ;  3,  posterior  lip  ;  4,  anterior  lip ;  5,  anus ;  6,  perineum ; 
7,  symphysis  pubis  ;  8,  fimbriated  extremity  of  the  Fallopian  tube  ;  9,  the 
€mpty  bladder — note  its  Y  shape,  and  also  that  the  walls  of  the  uterus, 
vagina,  urethra,  and  bladder  are  in  contact  except  when  distended  by  their 
appropriate  contents  (D.  Berry  Hart). 


PLATE  XXXII. 

Fig.  1 . — To  face  page  351, 


Posterior  View  of  Uterine  Appendages  :  1,  uterus  ;  2,  Fallopian  tube  ; 
3,  fimbriated  extremity  and  opening  of  the  Fallopian  tube  ;  4,  epooplioron  ; 
5,  ovary ;  6,  ligament ;  7,  ligament  of  the  ovary ;  8,  infundibulo-pelvic 
(broad)  ligament  (Henle). 


THE   FALLOPIAN   TUBES. — THE   OVAKIES.  351 

cles ;  hence  their  name,  ovules  of  Naboth.     At  the  upper  part  of  the 
cervix  the  cells  are  columnar  and  ciliated;  below,  stratified. 

What  are  the  ligaments  of  the  uterus  ? 

The  ligaments  of  the  uterus  are  the  round  ligaments  and  several 
peritoneal  folds — namely,  two  each  in  front,  behind,  and  laterally. 

The  round  ligaments  are  two  cord-like  bundles  of  areolar,  fibrous,  and 
plain  muscular  tissue,  with  vessels  and  nerves,  covered  by  peritoneum, 
which  run  from  the  upper  angle  of  the  uterus  to  the  internal  ring. 
Each  then  runs  through  the  corresponding  inguinal  canal  to  end  in  the 
mons  veneris  and  labia.  Each  measures  about  4  or  5  inches  in  length, 
and  their  direction  is  upward,  forward,  and  outward.  The  peritoneum, 
which  invests  them,  is  sometimes  prolonged  (as  in  the  foetus)  for  some 
distance  into  the  inguinal  canal,  and  forms  the  canal  of  Nuck.  Gene- 
rally this  canal  is  obliterated. 

The  anterior  or  vesico-uterine  ligaments  stretch  between  the  bladder 
and  the  uterus ;  the  posterior,  between  the  uterus  and  rectum,  hence 
called  the  recto-uterine^  forming  a  pouch,  the  cul-de-sac  of  Douglas. 

The  two  lateral  or  broad  ligaments  pass  from  the  sides  of  the  uterus  to 
the  sides  of  the  pelvis,  thus  dividing  the  latter  into  two  parts.  They 
are  formed  by  the  coalescence  of  the  peritoneal  layers  investing  the  ante- 
rior and  posterior  surfaces  of  the  uterus,  and  contain  between  the  two 
layers :  the  Fallopian  tube  at  the  upper  margin ;  the  round  ligament  be- 
low and  in  front  of  the  tube ;  the  ovary  and  its  ligament  enfolded  by  the 
posterior  layer ;  and  the  uterine  blood-vessels,  lymphatics,  and  nerves. 

THE  FALLOPIAN  TUBES. 
Describe  the  Fallopian  tubes. 

The  Fallopian  tubes,  or  oviducts,  run  from  the  upper  angles  of  the 
uterus  toward  the  sides  of  the  pelvis,  and  near  their  termination  bend 
downward,  backward,  and  inward.  They  are  3  to  4  inches  long,  are  at 
first  narrow,  then  enlarge  near  the  extremity  (ampulla),  and  end  in  a 
fimbriated  margin,  one  of  the  fimbriae  being  attached  to  the  ovary.  The 
canal  is  very  narrow  at  the  uterine  end  (ostium  uterinum),  begins  to 
widen  in  the  outer  half  to  form  the  ampulla,  and  at  its  termination  again 
narrows  (ostium  abdominale). 

The  tubes  consist  of  a  peritoneal  coat,  a  muscular  coat  composed  of 
internal  circular  and  external  longitudinal  fibres,  and  a  mucous  coat. 
The  latter  is  continuous  with  that  of  .the  uterus  and  with  the  perito- 
neum, the  epithelium  being  ciliated  columnar,  and  it  is  thrown  into  lon- 
gitudinal wrinkles,  more  marked  in  the  outer  half  of  the  tube. 

THE   OVARIES. 
Describe  the  ovaries. 

The  ovaries  are  analogous  to  the  testes,  and  are  flattened,  oval  bodies, 
measuring  IJ  inches  long,  |  inch  wide,  and  J  inch  thick,  each  weighing 


352  ORGAJsrs  of  reproduction  (female). 

60  to  100  grains.  Of  each,  the  two  sides  are  free  as  well  as  the  convex 
border,  the  straight  border  (hilus)  being  attached  to  the  broad  Hgament 
and  admitting  the  vessels,  etc.  Its  outer  end  is  attached  by  the  fimbria 
ovarica  to  the  Fallopian  tube,  its  inner  end  to  the  uterus  by  the  ligament 
of  the  ovary,  a  dense,  fibro-muscular  cord  attached  to  the  uterus  below 
and  behind  the  tube. 

The  ovary  consists  of  a  stroma  in  which  are  imbedded  the  Graafian 
follicles,  and  of  a  covering  of  columnar  cells,  the  germinal  epithelium. 
The  stroma  is  invested  beneath  the  epithelium  by  a  dense  fibrous  layer, 
the  tunica  albuginea,  and  consists  of  connective  tissue  with  numerous 
cells,  as  well  as  of  elastic  fibres,  with  some  muscular  tissue  and  blood- 
vessels. 

The  Graafian  follicles  consist  of  an  external  fibrous  coat,  and  beneath 
it  a  coat  called  the  ovi-capsule,  lined  internally  by  a  layer  of  cells,  the 
memhrana  granulosa.  Within  this  last-named  layer  is  the  ovum,  in- 
vested by  the  discus  proligerus,  a  layer  of  cells  derived  from  the  mem- 
brana  granulosa,  together  with  the  liquor  foUiculi. 

For  the  structure  of  the  ovum  see  Histology ^  or  Gynecology .  or  Ob- 
stetrics of  this  series. 

THE  PAROVARIUM. 

What  is  the  parovarium  ? 

The  parovarium,  organ  of  Eosenmiiller,  is  a  foetal  remnant  lying  in 
the  broad  ligament  between  the  ovary  and  Fallopian  tube.  It  consists 
of  several  vertical  tubes,  lined  by  epithelium,  whose  lower  ends  run 
toward  the  hilus  of  the  ovary,  and  whose  upper  ends  are  united  by  a 
horizontal  tube,  the  duct  of  Gaertner. 

THE  MAMMARY  GLANDS. 
Describe  the  mammary  glands. 

These  are  accessory  to  the  generative  system  and  secrete  the  milk. 
They  are  two  rounded  eminences,  one  on  each  side  of  the  thorax,  between 
the  sternum  and  axilla  and  the  third  and  seventh  ribs.  Just  below  the 
centre  is  a  conical  eminence,  the  nipple,  which  is  dark,  and  is  surrounded 
by  a  pinkish  areola  which  darkens  in  pregnancy.  ^  It  presents  the  orifices 
of  the  lactiferous  ducts,  and  consists  of  vessels  mixed  in  with  plain  mus- 
cular fibres,  and  by  friction  may  be  made  to  undergo  erection. 

The  mamma  consists  of  a  number  of  lobes  separated  by  fibrous  tissue 
and  some  adipose  tissue.  The  lobes  are  divided  and  subdivided  into 
smaller  lobules,  which  are  in  turn  made  up  of  alveoli.  ^  Each  lobe  has  an 
excretory  (galactophorous)  duct,  and  these,  about  sixteen  in  number, 
converge  to  the  areola,  there  dilating  into  ampulla'  or  sinuses.  They 
then  become  smaller  again,  and,  surrounded  by  areolar  tissue  and  ves- 
sels, pass  through  the  nipple  to  empty  on  the  surface  by  separate  orifices. 


GLOSSARY. 


F.  =  French ;  Gr.  =  Greek ;  L.  =  Latin ;  N.  L.  =  New  Latin  ;  adj.  =  adjective ;  c.  = 
common ;  dim.  =  diminutive ;  f.  =  feminine ;  m.  =  masculine  ;  n.  =  neuter  or 
noun;  part.  =  participle. 


Abdo'men,  inis,  n.  (L.)  =  venter.  [Etymology  doubtful.  Andrews:  Adipomen, 
from  adeps,  fat,  lard,  the  fat  lower  part  of  the  belly ;  Foster :  Abdere,  to 
conceal,  and  omen,  either  a  sign  in  ancient  augury  or  a  contr.  of  omentum — 
that  which  conceals  the  omen  or  omentum.  This  explanation  of  omen 
does  not  commend  itself;  men  is  a  formative  ending,  the  w^hole  word 
meaning  ''  the  concealer."]     The  belly,  paunch. 

Acerv'ulus,  i,  m.  (L.)  (aserv'ulus)  [dim.  of  dcervus,  i,  m.,  a  heap  ;  root  aJc,  per- 
haps related  to  agitare,  to  drive].  A  little  heap;  applied  to  a  collection 
of  "brain-sand"  in  the  pineal  gland. 

Acetab'ulum,  i,  n.  (L.)  [^ace'tum,  vinegar].  A  vinegar  vessel,  hence  any  cup- 
shaped  vessel.    The  articular  cavity  of  the  innominate  bone. 

Adminic'ulum,  i,  n.  (L.)  \^ad,  manus,  upon  the  hand].  The  stake  around  which 
the  vine  twines.     A  support. 

Afferent  [aff evens,  part,  from  ad,  to,  ferre,  to  carry].  Conveying  something 
from  the  periphery  to  the  centre. 

Ag'ger,  eris,  m.  (L.)  [aggerare,  to  heap  up].     A  heap  or  prominence. 

Alve^olar  (not  alveolar).     Pertaining  to  or  containing  alveoli. 

Alve'olus,  i,  m.  (L.)  [dim.  of  alv^us,  a  hollow].  Bone-socket  for  a  tooth  ;  an 
air-cell ;  a  part  of  a  gland. 

Anarogous  [avd,  \6yog,  according  to  due  ratio].  Referring  to  a  part  in  one 
organism  which  has  the  same  function  as  another  part  in  another  organ- 
ism; similarity  of  purpose.  "  When  organs  in  different  animals  agree  in 
structure  they  are  '  homologous ;'  when  they  perform  the  same  functions, 
they  are  '  analogous.'  The  wing  of  a  bird  and  arm  of  a  man  are  homolo- 
gous, not  analogous ;  the  wing  of  a  bird  and  the  wing  of  an  insect  are 
analogous,  not  homologous." 

Anas'tomo'sis,  is,  f.  (L.)  [avd,  of  each,  o-tojuow,  to  furnish  with  a  mouth,  to 
contract  to  a  narrow  mouth,  to  whet  the  appetite].  The  communication 
of  an  artery  or  vein  with  another  artery  or  vein. 

Anat'omy  [dvd,  apart,  refiveiv,  to  cut].  A  science  of  the  structure  of  organized 
bodies. 

Anco'neus,  a,  um,  adj.  or  n.  m.  (L.)  [ancon,  onis,  m..  =  dyKU}v,  the  bend  of  the 
arm].  Any  muscle  connected  in  any  way  with  the  olecranon ;  now 
applied  to  one  muscle  connected  with  the  triceps  and  olecranon. 

Annec'tant  [annecto,  ad,  to,  necto,  I  fasten  together].  Connecting.  Applied  to 
brain-tissue  that  connects  adjacent  gyri. 

Anti'cus,  a,  um,  adj.  (not  an'ticus)  (L.)  [ante,  before].     Anterior. 

Aor'ta,  ae,  f.  (L.)  [acpr^,  in  Hippocrates  the  bronchi;  from  aetpw,  I  lift  or 
heave].     The  common  trunk  of  the  systemic  arteries. 

Apoph'ysis,  is,  pi.  as,  f.  (L.)  (apof  isis)  [dirocfyvui].    An  outgrowth. 

Aq'ueduct  (L.  aquxductus,  us,  m.)  [aqua,  water,  ducere,  to  lead].  A  canal;  it 
may  or  may  not  contain  fluid. 

23— A.  353 


354  GLOSSARY. 

Arach'noid,  adj.  and  n.  (arak^noid)  (L.  arachnoid^ etis)  [apdxvri,  a  spider's  web, 
et5o9,  resemblance].  The  middle  of  the  three  membranes  investing  the 
brain  and  spinal  cord. 

Are'olar  (not  areo'lar)  [dre^^la,  se,  f.  dim.  of  area,  an  open  space].  Pertaining 
to  a  tissue  containing  interspaces. 

Ar'tery  (L.  arte'ria,  se,  f.  Gr.  aprrjpca)  [from  dpTJjp,  that  which  suspends;  origi- 
nally applied  to  the  trachea,  called  the  "rough  artery,"  rpax^la  apr-npia, 
suspending  the  lungs ;  perhaps  from  arip,  ae'pos,  air,  TTjpe'w,  1  convey.  The 
ancients  believed  it  contained  air,  being  found  empty  after  death].  A 
vessel  which  conveys  blood  from  the  heart. 

Aryte'noid  (L.  arytsenoid'eus,  from  arytse'na)  [dpuTatva,  a  ladle  or  pitcher,  ei5os, 
resemblance].  Shaped  like  the  mouth  of  a  pitcher.  A  cartilage  of  the 
larynx. 

Aste'rion,  ii,  n.  (L.)  [do-r^p,  star].  A  sort  of  spider ;  point  of  junction  of  pari- 
etal, occipital,  and  temporal  bones. 

Astrag'aliis,  i,  m.  (L.)  [do-rpdYaAos,  a  cervical  vertebra;  do-TpdyaXot  were  dice 
made  of  the  cubical  ankle-bones;  Lat.  tali  were  stone  dice].  The  ankle- 
or  sling-bone,  the  first  of  the  tarsus. 

Az'ygos,  n.  and  adj.  [d,  without,  ^vyov,  yoke].     Without  a  fellow;  unyoked. 

Basiric  [L.  basiVicus ;  Gr.  paaLkiK6<s,  royal,  from  /Sao-tAevs,  king;  perhaps  from 
Arabic  al-basilik,  the  inner].  A  superficial  vein  of  the  arm.  The  name 
was  applied  by  the  ancients  to  important  parts.  The  right  basilic  vein 
was  called  hepatic,  as  it  was  supposed  to  have  some  connection  with  the 
liver ;  for  a  similar  reason  the  left  basilic  vein  was  called  the  splenic;  the 
cephalic  veins  were  thought  to  be  connected  with  the  head,  and  whenever 
the  liver,  spleen,  or  head  was  diseased,  venesection  was  performed  on 
the  appropriate  vein. 

Bifur'cate  (not  bi'furcate)  [bis,  twice,  fiirca,  se,  f.,  a  two-pronged  fork].  To 
divide  into  two  branches. 

Blast'oderm  [^AaorTo?,  a  germ,  Sepixa,  skin].  A  membranous  bag  from  which 
the  embryo  is  formed. 

Breg'ma,  atis,  n.  (L.)  [/Spe'xetr,  to  moisten,  because  the  part  is  soft  and  moist  in 
infants].    Junction  of  coronal  and  sagittal  sutures. 

Caramus,  i,  m.  (L.)  [/cdAa/mo?,  a  reed  or  cane;  a  reed-pen].  C.  scriptorius, 
writing-pen.    A  portion  of  the  fourth  ventricle,  shaped  like  a  pen. 

CaFyx,  cal'ycis,  m.  (L.)  [Ka\vTTT<o,  I  cover].  A  cup.  The  outermost  leaflets  of 
a  flower;  a  cup-like  subdivision  of  the  ureter. 

Canine'  (kayneyn'),  L.  caninus  [canis,  a  dog].  Pertaining  to  or  resembling 
some  structure  in  a  dog. 

Canthus,  i,  m.  (L.)  [=  KdvOo^,  the  tire  of  a  wheel].  The  angle  of  junction  of 
the  upper  and  lower  eyelids. 

Capillary  (kap'illary  preferable  to  kapil'lary)  [capillus,  i,  m  or  um,  i,  n.,  hair 
of  the  head,  dim.  of  root  cap  {caput)].  Pertaining  to  hair  or  hair-like 
filaments. 

Carot'id  (L.  card'ticus)  [/coptuTtfies  (pi.),  the  carotids,  from  *cdpo?,  a  deep,  heavy 
sleep,  from  the  fact  that  drowsiness  can  be  produced  by  compression  of 
these  arteries  in  the  neck]. 

Caruncula,  ae,  f.  (L.)  [dim.  of  cdro,  carnis,  f.  flesh].  A  little  piece  of  flesh; 
caruncle. 

Cer'ebral  (not  cere'bral)  [L.  cerebra'lis].    Eelating  to  the  brain. 

Cer'ebrum,  i,  n.  (L.)  (not  cere'brum).  The  brain  as  a  whole;  the  principal 
part  of  the  brain,  including  the  hemispheres. 

Cervi'cal  (not  cer'vical)  [cervix,  cervi'cis,  f.,  neck;  L.  cervica'lis].  Pertaining 
to  the  neck  ;  neck  of  uterus, 


GLOSSARY.  355 

Cer'vix,  cervi'cis  (servi'sis),  gen.  pi.  cer'vicum,  f.  (L.)  Neck,  including  the 
nape. 

Chias'ma,  chias'matis,  n.  (L.)  (kiaz'ma)  [xtao-/xa,  from  x«*^<«>>  to  mark  with  xl- 
The  crucial  union  of  parts. 

Circumvallate  [dream,  around,  vallare,  to  surround  with  a  rampart].  Sur- 
rounded with  a  prominence. 

Cli'toris  (not  klit'oris),  clitor'idis,  f.  (L.)  [/cAeiropt?,  KAeiropt^eti/,  to  titillate,  or 
from  K\eULv,  to  shut  up,  or  from  kAtjtj^p,  a  servant  who  invites  guests].  A 
small  erectile  organ  in  the  vulva,  homologue  of  the  penis. 

Coccygeal  (koksij'eal,  not  koksige'al)  (L.  coccyg'eus).  Pertaining  to  the  coc- 
cyx or  tail. 

Coc'cyx  (kok'siks),  gen.  coccy'gis  (not  coc'cygis)  (L.)  [kokkv^,  a  cuckoo,  whose 
beak  it  resembles].     The  caudal  end  of  the  spinal  column. 

Coe'liac  (see'liak)  [/cotAta/cos  from  /coiAta,  the  belly].  Eelating  to  the  abdomen 
or  its  viscera. 

Com'es,  com'itis,  m.  or  f.  (L)  {cum,  with,  eo,  I  go].    A  companion. 

Con'dyle,  L.  condylus,  i,  m.  (con'dil)  [k6v8v\o^,  a  knot].     An  articular  process. 

Con'jugal  [conjux,  %is,  c.  spouse ;  con,  together,  jimgfo,  to  yoke].  Lig.  conju- 
gale,  united  with  its  fellow. 

Conniven'tes,  adj.  pi.  (L.)  [coimivens  entis,  from  con-niveo,  I  wink].  Folding 
on  each  other  {valvulse  c). 

Coro'nal  (not  cor'onal)  [coro'na,  se,  f.  Koptavn],  crown].     Relating  to  a  crown. 

Cran'ium,  ii,  n.  (L.)  [/cpavo?,  helmet,  or  from  Kpaviov,  skull].  The  brain-case; 
the  entire  skull. 

Cremas'ter,  cremaster'is,  m.  (L.)  [/cpeju.a<rT?7p,  a  suspender,  Kpefjidvvviii,  I  let  hang 
down].    The  suspensory  muscle  of  the  testicle. 

Crus'ta,  ae,  f.  (L.)  crust,  outer  coating.     Ventral  portion  of  the  crus  cerebri. 

Cu'bitus,  i,  m.,  or  cu'bitum,  i,  n.  (L.)  [cubo,  I  lie  dowin,  kv^ltov].  Elbow 
(serving  for  leaning  upon);  ulna;  forearm.  An  ell  or  cubit  (originally 
the  distance  from  the  elbow  to  the  end  of  the  middle  finger ;  the  Roman, 
17i  inches  ;  the  English,  18  inches;  the  Hebrew,  22  inches). 

Cu'neiform  [cuneus,  i,  m.  wedge,  forma,  form].     Wedge-shaped. 

Decus'sate  (not  de'cussate)  [decus'sis,  is,  m.  (decem-as),  a  ten-a>s  piece,  a  coin ; 
as  was  a  pound  weight,  or  16'i  cents.  As  the  Roman  numeral  on  the 
coin  was  X,  decussis  came  to  mean  the  intersection  of  two  lines].  To 
cross ;  to  place  in  the  form  of  an  X. 

Di'aphragm  [dy'afram),  L.  diapliragma,  atis,  n.  (dyafrag'ma)  [Sta^pav/xa,  a 
partition-wall ;  6ta,  thoroughly,  ^pao-o-w,  I  fence  in].  A  partition  between 
cavities.     The  partition  between  the  thoracic  and  abdominal  cavities. 

Diaph'ysis,  is,  f.  (diaf  isis)  (L.)  [5ta,  between,  (f>v€tv,  to  grow].  The  part  of 
bone  formed  from  the  principal  centre. 

Digas'tric  [8Cs,  twice,  yaa-rrip,  belly;  L.  biventer].     Having  two  bellies. 

Duode'nuin,  i,  m.  (L.)  [duodeni,  twelve  each].  Upper  portion  of  the  small 
intestine,  about  12  finger-breadths  (10  inches)  long. 

Efferent  [effei-ens,  part.,  ex,  from,  fer  re,  to  carry].  Carrying  or  leading  from 
an  organ. 

Em'bryo,  o'nis  (L.)  [efi^pvov,  eV,  within,  /Spvw,  to  be  full  of  anything].  The 
fecundated  ovum  in  the  first  two  or  three  months  of  its  development. 
(See  FcETUS.) 

Em'issary  [e,  out,  mittere,  to  send].    Serving  as  an  outlet. 

Ephip'pium  (effip'pium)),  ephip'pii,  n.  (L.)  [ini,  upon,  'imro^,  horse].  A  sad- 
dle ;  a  part  of  the  sphenoid  bone. 

Epiph'ysis  (epifisis),  is,  f.,  pi.  Epiph'yses  (L.)  [ini,  upon,  <f>v€Lv,  to  grow]. 
The  portion  of  a  long  bone  from  a  secondary  or  tertiary  centre. 


356  GLOSSARY. 

Epiplo'ic  (L.  epiplo'icus,  a,  urn,  adj.)  [en-tTrAooi',  omentum,  ctti,  upon,  TrAe'co,  I  float]. 
Pertaining  to  the  omentum. 

Epipter'ic  (epipter'ik)  [eTrt,  upon,  -nTepov,  wing].  Situated  on  the  greater  wing 
of  the  sphenoid. 

Eustach'ius  (Bartholomeo  Eustachi),  of  the  Italian  school  (1500),  was  the  con- 
temporary of  Vesalius,  and  divides  with  him  the  merit  of  creating  the 
science  of  anatomy.    He  studied  especially  the  internal  ear. 

Exore'tory  \^ex,  out,  cerno,  I  choose].  Pertaining  to  excretion  (the  separation 
from  the  body  of  parts  supposed  to  be  useless). 

Fac'et  (not  faset')  (F.)  [dim.  of /ace].    A  small  face. 

Fallopius  was  a  pupil  of  Vesalius,  and  professor  at  Padua  in  1551 ;  studied 
bones,^especially  the  internal  ear  and  organs  of  generation. 

Ferrugin'eus,  a,  um,  adj.  (L.);  also  ferrug'inus  [ferriigo,  iron-rust,  from  fer- 
rum,  iron].     Of  the  color  of  iron-rust;  dusky. 

Foetus,  lis,  m.  (strictly  fetus)  (L.)  [from  root  feo,  whence  also  fecundus  and 
felix,  fruitful ;  femina,  fruit-bearer ;  fenus,  interest  or  gain].  The  unborn 
child.  In  the  human  subject  this  term  is  usually  applied  to  the  embryo 
only  after  the  third  month  of  gestation. 

Fontanelle  (fontanel')  (F.)  [fontanella,  se,  t,  dim.  of  fons,  fontis,  a  fountain]. 
A  membranous  interspace  between  foetal  skull-bones.  Pulsation  like  a 
fountain  is  here  seen. 

Fo'vea,  ae,  f.  (L.)  [fodio,  ere,  to  dig].  A  small  pit,  a  pitfall.  An  old  term  for 
the  vulva. 

Gal'ea,  ae,  f.  (L.)  [yaAeTj,  weasel,  from  the  skin  of  which  helmets  were  made]. 
Helmet ;  the  amnion. 

Ga'len,  L.  Claudius  Galenus  \ya\av6<;,  calm].  The  greatest  anatomist  of  antiq- 
uity, lived  in  Pergamus  and  Eome;  died,  set.  90,  in  193  a.d.  Wrote  in 
Greek ;  he  described  the  bones  and  sutures  of  the  cranium,  the  vertebrae, 
the  thorax,  nearly  in  the  same  manner  as  at  present.  He  described  the 
facial,  maxillary,  and  neck  muscles,  naming  one  the  platysma  myoides. 
He  proved  that  arteries  contained  blood,  not  air.  His  death  marked  the 
downfall  of  ancient  anatomy. 

Gallinag'o,  gallinaglnis,  f.  (L.)  [gallVna,  ss,  hen].  The  wood-cock.  Caput 
gal.,  syn.  of  verumontanum. 

Glabel'la,  ae,  f.  (L.)  [glahellus,  a,  um,  dim.  of  glaber,  smooth,  without  hair]. 
The  part  of  the  frontal  bone  between  the  superciliary  ridges. 

Glans,  glandis,  f.  (L.).  An  acorn.  Any  object  resembling  a  nut,  as  the  head 
of  the  penis  or  clitoris,  a  suppository,  a  pessary,  a  goitre. 

Hal'lex,  hal'licis,  or  allex,  alUcis,  m.  (L.)  [aWoixai,  to  leap].  The  great  toe  or 
thumb.  (There  is  no  authority  for  hallux,  hallucis ;  hallus  or  alius,  kindr. 
with  allex,  has  the  gen.  alii.  Alex,  alecis,  f.  and  m.,  fish-brine  or  sedi- 
ment.) 

Belicotre'ma,  helicotre'matis,  n.  (L.)  [e'Aif,  helix,  spiral,  TpTiixa,  hole].  An 
aperture  at  the  apex  of  the  cochlea. 

Hemorrhoid'al  [hsemor'rho'is,  idis,  f.,  alfioppot^,  usually  in  pi.  supply  <f)\ep€^, 
veins;  alfia,  blood,  pew,  I  flow,  run].     Pertaining  to  hemorrhoids. 

Heroph'ilus,  i,  m.  [epw?,  hero,  <^iAe(u,  I  love].  An  anatomist  of  the  Alexan- 
drian school,  304  B.  c.  He  described  the  venous  sinuses,  and  first  applied 
the  names  duodenum,  choroid,  and  calamus  scriptorius. 

Hi'lum,  i,  n.  (L.),  hilus,  i,  m.  (N.  L.)  [from  nihilum  =  nihil,  nothing,  a  trifle]. 
The  black  spot  on  the  base  of  a  bean.  The  point,  depressed  or  elevated, 
of  an  organ  where  the  vessels  and  nerves  enter  it  and  its  excretory  duct 
leaves  it. 

Hippooam'pus,  i,  m.  (L.)  [iVTro/cajuiTros,  tTTTTos,  horse,  Kajonrrw,  I  bend ;  a  monster, 


GLOSSARY.  357 

with  a  horse's  body  and  fish's  tail,  on  which  the  sea-gods  rode].  Sea- 
horse; projection  of  white  matter  into  the  lateral  ventricle  of  the  brain. 

Hippoc'rates,  is,  m.  ['l7r7ro/cpaT»js,  itttto?,  horse,  /cparo?,  strength,  control].  A 
Greek  physician  of  Cos,  the  father  of  medicine,  460-377  B.  c. 

Homorogous  [6/x6?,  common,  \6yos,  understanding].  Like  a  given  standard; 
constructed  on  the  same  plan.     (See  Analogous.) 

Impar,  aris  (L.)  adj.  [im,  negative,  par,  equal].    Unequal,  odd. 

I'mus,  a,  um,  adj.  (L.)  [infh^us,  that  is  below;  inferior,  lower;  inftmus  or 
imus,  lowest,  last].     Lowest. 

Incisi'vus,  adj.  and  n.  (L.)  [iw,  csedere,  to  cut  into].  Incisive;  a  muscle  near 
the  incisor  teeth. 

Ingrassias,  John  Philip,  1545-80,  a  Sicilian  physician,  made  osteology  a  spe- 
cialty ;  described  the  sphenoid  and  ethmoid,  and  first  described  the  stapes. 

In'ion  (N.  L.)  [Ivlov,  back  of  tlie  head].     External  occipital  protuberance. 

Intes'tine  (L.  intestVnum,  i,  n.)  [inUis,  within  ;  cf.  evrepov,  from  evros,  within]. 
The  canal  from  the  stomach  to  the  anus. 

Ischiad'icus,  a,  um,  adj.  (L.)  [to-xtaStfos,  subject  to  pains  in  the  loins,  laxCov, 
hip-joint].  That  has  gout  in  the  hip.  Pertaining  to  the  ischium.  (See 
Sciatic.) 

Is'«hiuinj  ii,  n.  (is'kium)  (L.)  [la-xiov,  hip-joint,  from  iaxvw,  I  am  strong,  or 
from  lo-xw,  I  hold,  I  stop;  supporting  the  trunk  when  seated].  The 
lower  part  of  the  os  innominatum. 

Jeju'num,  neut.  sing,  oi  jeju'nus,  a,  um,  adj.  (L.).  Fasting,  hungry.  The 
upper  two-fifths  of  the  small  intestine  below  the  duodenum ;  so  called 
because  it  was  supposed  to  be  empty  after  death. 

Ju'gular  (not  jug'ular)  (L.  jugularis,  e)  [juguhim,  i,  n.,  the  throat,  dim.  of 
jugum,  the  yoke,  which  was  attached  there].  Pertaining  to  the  neck  or 
throat. 

Laryn'geal  (not  larynge'al).    Pertaining  to  the  larynx. 

Lateral'is,  e  (L.)  [latus,  Ms,  n.,  the  side].  Pertaining  to  the  side  (external, 
Henle). 

Lig'ula,  ae,  f.,  and  Lin'gula,  se,  f.  (L.)  [dim.  of  lingua,  tongue].  A  little 
tongue.  Ligula  is  applied  to  white  matter  bounding  the  floor  of  the 
fourth  ventricle. 

Ma'lar  [mala,  se,  f.,  cheek-bone].    Pertaining  to  the  cheek-bone. 

Malle'olus,  i,  m.  (not  malleo'lus)  (L.)  [dim.  of  maMus,  mallet].  The  project- 
ing lower  extremity  of  the  tibia  or  fibula. 

Malpighi,  middle  of  seventeeth  century,  is  the  founder  of  histological  anat- 
omy, as  he  used  the  microscope.  His  name  is  associated  with  the  deeper 
layer  of  the  skin  and  the  bodies  in  the  kidney  and  spleen. 

Masse'ter,  er'is,  m.  (not  mas'seter)  (L.)  [juao-o-rjTTjp,  from  fiaadofiai,  I  chew]. 
(See  Maxilla.)     Name  of  a  muscle  of  the  lower  jaw. 

Maxil'la,  88,  f.  (L.)  [dim.  of  mala,  se,  f.,  the  jaw  or  cheek,  from  mando,  from 
fxaadofxai,  I  chew,  akin  to  /xaw  and  ixdaaui,  I  knead].  The  jaw-bone.  The 
upper  jaw-bone,  the  lower  being  the  mandible. 

Medial'is,  e  (L.)  [medius,  middle].  Pertaining  to  the  median  part  (internal, 
Henle). 

Mediasti'num,  i,  n.  (L.)  [mediasti'nus  is  the  same  as  medius,  and  more  elegant 
than  that  short  adj. ;  it  is  not  a  corruption  of  per  medium  tensum,  some- 
thing stretched  between  (Hyrtl)].  A  partition.  Properly  the  cavum 
mediastini. 

Med'ullary  (med'ullary  preferable  to  medul'lary)  [medulla,  se,  f.,  pith,  medius, 
in  the  middle].     Pertaining  to  medulla  or  marrow. 

Menin'geal  (not  meninge'al).    Pertaining  to  the  menin'ges. 


358  GLOSSARY. 

Mes'entery  [ixeaivTepov,  /ixeo-o?,  middle,  evT^pov,  intestine].   A  fold  of  peritoneum 

by  which  the  jejunum  and  ileum  are  attached  to  the  abdominal  wall;  a 

fold  by  which  any  organ  is  attached. 
Modi'olus,  i,  m.  (L.)  {dim.  of  modius,  a  peck].    The  hub  of  a  wheel ;  the  cen- 
tral axis  of  the  cochlea. 
Mus'cle  [dim.  of  mus,  muris,  a  mouse,  musculus,  a  little  mouse,  as  muscles  were 

said  to  resemble  flayed  mice ;  more  probably  from  fuvhv,  to  close].   Animal 

tissue  composed  of  contractile  fibres. 
My'lo-  [fvAtj,  a.  mill,  from  jolv'w,  /uu^w,  to  make  the  sound  tiv  (xv  with  closed  lips, 

to  murmur].    Keferring  to  the  jaw,  especially  the  lower,  or  to  the  molar 

teeth. 
Myoi'des  [jau?,  muscle,  elSos,  resemblance].     Like  a  muscle. 
My'otomes  (L.  pronunc.  myot'mes)  [m-vs  (/u-vw,  to  keep  close),  a  muscle,  rojun?, 

a  section,  from  reixvu)].    A  series  of  dark  paired  masses  on  each  side  of  the 

notochord,  producing  the  muscular  segments  of  the  body ;  provertebrse ; 

mesoblastic  somites. 
No'ni,  gen.  sing,  of  norms,  a,  um,  adj.  (L.)  [for  novenus,  from  novem,  nine]. 

Of  the  ninth;  referring  to  the  hypoglossal  or  ninth  cranial  nerve  (old 

classif.). 
Nu'cha,  86,  f.  (L.).    The  hinder  part  or  nape  of  neck. 
Obe'lion  (N.  L.)  [ojSeAo?,  a  spit,  obelisk;  a  horizontal  line  with  a  point  above 

and  one  below,  h-,  was  used  to  point  out  superfluous  passages  (kindr.  with 

ojSoAds,  a  coin)].     A  point  in  the  sagittal  suture  between  the  parietal 

foramina. 
Oph'ryon  (off'rion)  (N.  L.)  [o(/)pu9,  eyebrow;  L.  supercilium].    Where  the  supra- 
orbital line  crosses  the  median  line. 
Opis'thion  (N.  L.)  [oTnVeio?,  hinder  part].    Middle  of  posterior  margin  of  the 

foramen  magnum. 
Oppo'nens,  entis  (not  op'ponens)  (L.)  [part,  from  oh,  against,  and  pono,  I 

place].    Standing  against ;  opposing. 
Os,  ossis,  pi.  ossa,  n.  (L.).     Bone.    Os,  oris,  pi.  ora,  n.  (L.).    Mouth. 
Palpebral  (not  palpe'bral)  (L.  palpebrd'lis)  [paVpebra,  se,  f.,  or  paVpebrum,  i,  n., 

an  eyelid].    Pertaining  to  the  eyelid. 
Papyra'ceus,  a,  um,  adj.  (L.)  [papyrus,  i,  m.  or  f.,  TraTrvpo?,  an  Egyptian  rush 

or  flag,  from  the  inner  rind  of  which  paper  was  made].    Like  papyrus  or 

paper. 
Pectin'eus  (not  pectine'us),  adj.  and  n.  (L.)  [pecten,  mis,  m.,  a  comb,  the  hair 

of  the  privates].    Name  of  a  muscle  rising  from  the  os  pubis. 
Peritonae'um  and  Peritone'um,  i,  n.  (L.)  =  Trepiroi'atoi/  and  irepiToveiov   [nepi, 

around,  reiVw,  I  stretch].    A  serous  membrane  stretched  over  the  abdom- 
inal viscera  and  lining  the  abdominal  cavity. 
Pilas'tered  [pilas'ter  {pila,  a  pillar)  is  a  square  pillar  inserted  into  a  wall, 

projecting  a  little  from  its  surface].    Furnished  with  pilasters. 
PT'neal  [pi'nea,  se,  f.,  pine-cone].     Resembling  a  pine-cone. 
Platys'ma  (L.)  [nKdTvaixa,  anything  spread  out,  from  TrAarv?,  wide].    A  muscle. 
Poplit'eal  (not  poplite'al)  [poples,  poplitis,  m.,  ham  of  the  knee  (posterior  part 

of  knee)].     That  which  relates  to  the  ham- 
Por'ta,  88,  f.  (L.)  [root  par,  a  place  through  which  things  are  carried].   A  gate ; 

the  part  of  the  liver  where  vessels  enter  as  by  a  gate.     ( Vena  portse,  not 

vena  porta.) 
PostT'cus,  a,  um,  adj.  (L.)  [post,  behind].    That  which  is  behind;  posterior. 
Pre'puce  CL.  prseputium)  [irpo,  before,  Trdo-arj,  penis  (?)].     The  foreskin. 
Process  (pr5c'es;  pro'cess  accord,  to  Lat.  quantity)  [procedure,  to  go  forth]. 

A  prominence  or  projecting  part. 


GLOSSARY. 


^e  ill 


Pros'tate  [npo,  before,  la-rrj/xt,  I  stand].     A  gland  situate^'l^eiore  the  neck  of\ 
the  bladder  in  the  male.  J 

Pter'ion  (ter'ion)  or  Pte'ron  (N.  L.)   [nTepov,  a  feather  or  bird's  wing,  from 

TreTo/utat,  I  fly].    Spheno-parietal  suture.  i  ft     y     I  /J'O'  {?     »«    n 

Pu'bes,  pii'ber,  pu'bis,  eris,  adj.  (L.).    That  is  grown  |p7Adi!lt.  ypG/befivik  4*Ji  Ui 
The  signs  of  manhood — i.  e.  the  hair  of  the  pri^tes  or  the  beard ;  the 
privy  parts.     Os  pubis,  the  bone  of  the  pubes  (geAcase). 

Pyram'idal  {1j. pyramidal' is,  e),  adj.  [TrupajLttv,  i5o?  (probablj^^ptian).   Ancients 
derived  it  from  nvp,  flame,  because  of  its  pointed  sl^g^  also  from  irvpo^^ 
wheat,  as  if  pyramids  had   been   granaries].     Shape 
Name  of  two  muscles. 

Ra'nine  [rdna,  se,  f.,  a  frog,  a  swelling  under  the  tongue] 
Applied  to  certain  vessels  of  the  tongue. 

Raph'e  (raf'e)  (N.  L.)  [pacfyri,  a  seam,  pdirria,  I  sew].     A  ridge  or  suture.  _ 

Rhomboid'eus,  adj.  or  n.  (L.)  [pofx^o^,  a  figure  whose  sides  are  equal,  with  two 
acute  and  two  obtuse  angles;  elSos,  resemblance].     A  muscle  of  the  back. 

RT'ma,  ae,  f.  (L.)  [rigma,  from  ringor,  I  open  the  mouth].     Chink,  fissure. 

Sagit'tal  (not  sag'ittal)  [sagifta,  se,  f.,  arrow].  Eesembling  an  arrow.  Per- 
taining to  a  vertical  mesial  plane  of  the  body  or  any  plane  parallel  to  it. 

Saphe'nous  [o-a<|>^9,  distinct,  manifest].  Applied  to  some  superficial  veins  of 
the  lower  extremity,  to  nerves,  and  to  an  "  opening." 

Scala,  ae,  f.  (L.)  [scando,  h^e,  I  climb].    A  staircase;  a  ladder. 

Scanso'rius,  a,  um,  adj.  (L.)  [scando,  scansum,  I  climb].     Of  or  for /ilimbing. 

Sciat'ic  (syat'ik)  (contraction  of  ischiatic)  [lax^ov,  strictly  the  acetabulum; 
the  haunch  or  hip.  Prob.  from  io-xv?,  strength].  Eelated  to  or  connected 
with  the  ischium. 

Secre'tory  [se,  aside,  cerno,  I  choose  or  put].  Pertaining  to  secretion  (the  sepa- 
ration from  the  blood  of  parts  supposed  to  be  useful  to  the  animal  economy). 

Sinister,  tra,  trum,  adj.  (L.)  (obs.  sinis'ter).  On  the  left  hand  ;  left.  (In 
the  Roman  sense  lucky ;  in  the  Greek  sense  unluclcy.  In  consulting  aus- 
pices the  Eomans  turned  the  face  to  the  south,  and  so  had  the  eastern  or 
fortunate  side  to  the  left ;  while  the  Greeks,  turning  to  the  north,  had  it 
on  their  right.) 

SoPeus,  i,  m.  (L.)  [soUa,  se,  f.,  the  sole  of  a  shoe,  sandal].  A  muscle  of  the 
calf  of  the  leg ;  named  from  its  shape. 

Somat'opleure  [aSifxa,  body,  -rrkevpa,  a  rib,  the  side,  lining  membrane  of  the 
chest].     Outer  leaf  of  blastoderm,  producing  the  body- walls. 

So^mites  (L.)  (L.  pronunc.  so'mi  tes)  [aiafxa,  o-w/uaTos,  body].  Segments  of  the 
body  or  mesoderm. 

SplanchnoPogy  [a-irKdyxvov,  pi.  a,  viscera,  A.6yos,  treatise].  The  part  of  anatomy 
relating  to  viscera. 

Splanch'nopleure  [a-TrXdyxvov,  viscera,  inward  parts,  TrAeupa,  the  pleura].     Inner 
_leaf  of  the  blastoderm,  forming  the  alimentary  canal. 

Sple'nic   [splen,  splenis,  m.,  also  lien,  enis,  m. ;  a-n\riv,  jjro?,  the  milt,  spleen]. 
_Relating  to  the  spleen. 

Sple'nium,  ii,  n.  (L.)  [o-ttA^j',  spleen].  A  patch,  pad  (because  like  the  spleen 
in  shape). 

Sple'nius,  a,  um,  adj.  or  n.  (L.)  [(rnKrjvLov,  a  bandage,  compress;  <Tn\rjv,  o-TrArji/d?, 
spleen].  A  muscle  of  the  back  and  neck,  said  to  resemble  in  shape  the 
spleen  of  certain  animals. 

Stapedius,  ii,  m.  (L.)  [std'pes,  sfd'pedis  {sto,l  stand;  pes,  pedis,  a  foot),  stir- 
rup].    A  muscle  of  the  middle  ear  attached  to  the  stapes. 

Stephan'ion  (N.  L.)  [o-rec^ai/o?,  crown,  from  o-re^oj,  I  encircle].  The  point  where 
the  coronal  suture  crosses  either  one  of  the  temporal  lines. 


360  GLOSSARY. 

Sutu'ra,  86  (not  soot'ura),  f.  (L.)  [suo,  I  sew  or  stitch].    Suture;  a  dovetail 

joint;  an  immovable  articulation. 
Syl'vius,  Jacobus  {Jacques  Dubois),  1478-1555  A.  d.,  was  of  the  French  school, 

and  taught  anatomy  in  Paris.     He  was  coarse,  envious,  and  jealous,  made 

no  original  research,  but  acquired  a  great  reputation.     Parts  of  the  brain 

bear  his  name. 
Syn'ohondro'sis,  pi.  es  (N.  L.)  [  o-vV,  with,  xo^Spo^,  cartilage].    Union  of  bones 

by  means  of  cartilage. 
Syn'desmo'sis,  pi.  es  (N.  L.)  [o-uV,  with,  5eo-/x6s,  band  (Seo),  I  tie].    Union  of 

bones  by  means  of  ligament. 
TaB'nia,  ae,  f.  (L.)  [ratna,  a  band;  TeiVw,  to  stretch].     A  band,  ribbon,  fillet;  a 

tape- worm. 
Talus,  i,  m.  (L.)   [a  die  made  of  knuckle-bones,  marked   on  four  sides]. 

The  ankle ;  the  heel ;  the  astragalus. 
Tento'rium,  ii,  n.   (L.)   [tendo,  retVw,  I  stretch].    A  tent;  the  dura  mater, 

which  covers  the  cerebellum. 
Tes'ticle  [testic'ulus,  dim.  of  testis,  is,  m. ;  pi.  testes ;  a  witness,  because  the 

testicles  are  witnesses  of  manly  vigor].   A  glandular  organ  in  the  scrotum 

which  secretes  sperm. 
Thalamus,  i,  m.  (L.)  [6akaixo<i,  an  inner  room,  a  bed,  bridal-chamber,  a  den]. 

A  central  ganglion  of  the  brain. 
Thy'roid  or  Thy'reoid  [Bvp^o^,  an  oblong  shield,  from  Bvpa,  a  folding-door,  elfio?, 

resemblance].     Applied  to  a  cartilage  of  the  larynx,  also  to  a  gland  and 

various  vessels. 
Trache'a  (L.  pronunc.)  (L.  trdchia)  [rpaxeia,  from  Tpaxv<;,  rough].     The  wind- 

pipe. 
Tri'gone  (try'gohne)  (F.)  [from  trigonium,  ii,  n.  =  Tpiyotvov,  rpeiq,  three,  ytavia, 

corner].    A  triangle. 
Trique'trus,  a,  um  (trykwee'trus)  (L.)  [^res,  three].     Having  three  corners. 
Tritic'eus,  a,  um,  adj.  (L.)  [from  triticum,  n.,  wheat,  from  tero,  I  rub  or  grind]. 

Like  a  kernel  of  wheat. 
Trochlea,  ae,  f.  (L.)  (trok'leah)  [rpoxos  (Tpexw),  a  runner,  anything  round  or 

circular].    A  pulley ;  a  surface  grooved  like  a  pulley. 
Tym'paiiic  (not  tympaii'ic)  [rvfinavov,  a  kettle-drum,  tutttw,  I  beat].    Eefer- 

ring  to  the  tympanum,  ear-drum. 
TTmbili'cal  (not  umbirical).     Eelating  to  the  navel. 
UmbilT'cus,  i,  m.  (L.)  [6ju,<^aA69,  navel,  akin  to  ajujSwv,  umbo,  boss  of  a  shield]. 

The  navel ;  the  centre. 
TJ'rachus,  i    (JST.  L.)  (not  urak'us)  [ovpov,  urine,  exetv,  to  hold].    A  band  from 

the  bladder  to  the  umbilicus ;  in  the  foetus  extended  to  the  allantois. 
TJre'ter  (not  u'reter),  eris  ''N.  L.)  [ovpryr^p  =  ovpridpa,  from  ovprjw,  I  make  water]. 

The  excretory  canal  from  the  kidney  to  the  bladder. 
Vagi'nal  (not  vag'inal)   [vagina,  se,  f.,  a  sheath].     Relating  to  the  vagina; 

sheath-like. 
Vesalius,  Andrew,  a  native  of  Brussels,  1514-64,  was  a  pupil  of  Sylvius.    He 

was  the  first  author  of  a  comprehensive  view  of  human  anatomy;  has 

been  called  its  founder.     He  fully  described  the  sphenoid,  sternum,  and 

vestibule  of  the  internal  ear ;  discovered  and  named  the  ductus  venosus, 

and  gave  a  full  description  of  the  brain. 
Vesical  (accord,  to  L.  quantity  vesi'cal ;  cf.  cervi'cal,  umbili'cal,  vagi'nal) 

[vesVca,  se,  f.,  a  bladder,  especially  urinary].     Relating  to  the  bladder. 
Ver'umonta'num  (L.)  [veru,  us,  n.,  a  spit,  montanus,  a,  um,  adj.,  mountain]. 

An  elevation  on  the  floor  of  the  urethra. 


INDEX. 


Acetabulum,  77,  79 
Adminiculum,  146 
Agger  nasi,  49 
Air-sinuses,  61 
Ala  cinerea,  265 
Amphiarthrodial  joints,  93,  94 
Angeiology,  19,  204 
Angle  of  pubis,  78 

sacro-vertebral,  28 

subcostal,  34 
Ankle-joint,  132 
Annulus  inguinalis,  146,  149 
Antrum  mastoideum,  41 

of  Highmore,  48,  50 
Aorta,  208 
Aponeurosis,  epicranial,  106 

intercostal,  156 

lumbar,  142 

of  abdominal  muscles,  147,  148 

of  arm,  174 

of  forearm,  176 

of  leg,  194 

pharyngeal,  158 

vertebral,  142 
Aqueduct  of  cochlea,  43 

of  Sylvius,  262 

of  vestibule,  42 
Arch,  crural,  149 

of  aorta,  208 

palmar,  222 

plantar,  232 

subpubic,  80 
Arachnoid,  249,  252 
Area  cribrosa,  42 

Artery  or  Arteries,  anastomotica  mag- 
na, 221,  229 

angular,  212 

aorta,  208 
abdominal,  223 
thoracic,  223 


Artery  or  Arteries,  axillary,  219 
basilar,  218 
brachial,  220 
brachio-cephalic,  209 
.    bronchial,  223 
carotid,  210,  214 
centralis  retinae,  216 
cerebellar,  217,  218 
cerebral,  216,  218 
cervical,  218 
choroid,  216,  218 
circumflex,  220,  230 

iliac,  229 
cceliac  axis,  224 
colica,  225 
comes  nervi  ischiadici,  228 

phrenici,  219 
coronary,  212 
cremasteric,  229 
dental,  214 
dorsalis  hallicis,  231 

indicis,  222 

pedis,  231 

pollicis,  222 
epigastric,  219,  228,  229 
facial,  211,  213 
femoral,  229 
gastric,  224 
gastro-duodenalis,  224 
gastro-epiploica,  224,  225 
gluteal,  226 
hemorrhoidal,  225,  257 
hepatic,  224 
iliac,  226,  228 
ileo-colic,  225 
ilio-lumbar,  226 
innominate,  209 
intercostal,  219,  223 
internal  mammary,  219 

maxillary,  213 
interosseous,  222 
labial,  212 

361 


362 


INDEX. 


Artery  or  Arteries,  laryngeal,  211,  228 
lingual,  211 
lumbar,  224 
mastoid,  212 
median,  222 
medullary,  20 

meningeal,  212,  213,  214,  217 
musculo-phrenic,  219 
nasal,  214,  216 
obturator,  227 
occipital,  212 
ophthalmic,  215 
orbital,  213 
ovarian,  226 
palatine,  212,  214 
pancreatico-duodenal,  224,  225 
perineal,  227 
peroneal,  232 
pharyngeal,  213 
phrenic,  224 
plantar,  232 
popliteal,  230 
princeps  cervicis,  212 

pollicis,  222 
profunda,  220,  230 

cervicis,  219 
pudic,  227,  229 
pyloric,  224 
radial,  221 
radialis  indicis,  222 
ranine,  211 
receptaculi,  215 
renal,  225 
sacral,  224,  226 
scapular,  218,  220 
sciatic,  228 
sigmoid,  225 
spermatic,  226 
splenic,  224 

sterno-mastoid,  211,  212 
stylo-mastoid,  213 
subclavian,  216 
subscapular,  220 
superficialis  volse,  221 
suprarenal,  225 
suprascapular,  218 
temporal,  213,  214 
thyroid,  211,  218 

axis,  228 
tibial,  231,  232 
tonsillar,  212 
tympanic,  213,  215 
ulnar,  222 
uterine,  227 


Artery  or  Arteries,  vaginal,  227 

vertebral,  217 

Vidian,  214 
Arthrology,  19,  93 
Articulations,  ilio-sacral,  121 

of  costal  cartilages  and  sternum,  101 

of  lower  extremity,  120 

of  ribs  and  vertebrae,  99 

of  trunk  and  head,  95 

of  upper  extremity,  104 

of  vertebral  column,  95 

temporo-maxillary,  103 
Asterion,  64 
Auricles,  205 
Auricular  point,  64 

B. 

Basion,  64 

Bladder,  339 

Bone  or  Bones,  analysis  of,  22 

astragalus,  86 

atlas,  24 

axis,  25 

clavicle,  64 

cuboid,  88 

cuneiform,  73,  87,  88 

epihyal,  104 

epipteric,  56 

ethmoid,  47 

femur,  80 

fibula,  85 

frontal,  38 

humerus,  67 

hyoid,  35 

iliac,  77 

incus,  303 

innominate,  76 

intermaxillary,  50 

ischium,  78 

lachrymal,  53 

lunar,  73 

malar,  52 

malleus,  303 

maxillary,  48,  54 

metacarpal,  75 

metatarsal,  88 

nasal,  53 

navicular,  87 

number  of,  22 

occipital,  35 

of  Bertin,  45 

of  carpus,  72 

of  cranium,  35 


INDEX. 


363 


Bone  or  Bones  of  face,  35,  48 

of  foot,  89 

of  the  head,  35 

of  lower  extremity,  76 

of  palm,  75 

of  tarsus,  86 

of  trunk,  23 

of  upper  extremity,  64 

palate,  50 

parietal,  37 

patella,  83 

phalanges,  76,  89 

pisiform,  73 

pubic,  78 

pyramidal,  73 

radius,  71 

scaphoid,  73,  87 

scapula,  67 

semilunar,  73 

sesamoid,  78,  89 

sphenoid,  44 

spongy,  45,  48 

stapes,  303 

talus,  86 

temporal,  39 

tibia,  83 

trapezium,  73 

trapezoid,  74 

turbinate,  54 

ulna,  70 

unciform,  74 

vomer,  52 

Wormian,  56 
Brain,  252 
Bregma,  63 
Bronchi,  314 
Bursse,  carpal,  183 

intertubercularis,  109 

of  elbow-joint,  111 

of  hip-joint,  125 

of  knee-joint,  127,  130 

of  Monro,  106 

of  shoulder-joint,  109 

prepatellar,  130 

pretibial,  128 

retro-epi  trochlear,  1 12 

subacromial,  104 

subcrural,  127 

subpatellar,  128 


Calamus  scriptorius,  265 
Calcar  avis,  259 


Calcar  femorale,  82 
Calvaria,  59 
Canal,  crural,  187 

dental,  49,  53 

Hunter's,  192 

internal  orbital,  57 

malar,  53 

medullary,  18 

neural,  18 

of  Huguier,  40 

of  nasal  duct,  49 

orbital,  38 

palatine,  49,  51 

pterygo-palatine,  46,  51 

sacral,  29 

semicircular,  305 

spinal,  31 

temporal,  53 

vomero-basilar,  52 
.^Canaliculus  innominatus,  47 
Cerebellum,  262 
Chiasma,  258,  266 
Chordae  tendinese,  206 
Circle  of  Willis,  218 
Claustrum,  260 
Clitoris,  348 

Clivus  Blumenbachii,  44 
Coccyx,  29 
Cochlea,  305 
Coelom,  18 
Colon,  328 
Concha,  301 

Conchse  sphenoidales,  45 
Conus  arteriosus,  206 
Cornea,  298 
Cornucopia,  265 
Corpus  albicans,  258 

Arantii,  206 

callosum,  257,  259 

fimbriatum,  260 

quadrigeminum,  262 

striatum,  260 
Costal  cartilages,  33 
Crest,  frontal,  39 

incisor,  49 

infratemporal,  45 

lachrymal,  53 

nasal,  49 

obturator,  78 

occipital,  36 

of  pubis,  78 

of  tibia,  84 

sphenoidal,  45 

supramastoid,  39 


364 


INDEX. 


Crest,  temporal,  38 

turbinate,  49,  51 
Crista  falciform  is,  42 

galli,  47 

orbitalis,  59 
Crus  cerebri,  258 
Crystalline  lens,  300 

I>. 

Dartos,  145 
Deglutition,  164 
Development  of  ovum,  17 
Diaphragm,  152 
Diarthrodial  joints  93,  94 
Duodenum,  325 
Dura  mater,  249,  252 

E. 

Ear,  301 

Elbow-joint,  110 
Embryology,  17 
Eminence,  deltoid,  68 

frontal,  38 

nasal,  38 

hypothenar,  184 

thenar,  184 

ilio-pectineal,  77 

olivary,  44 
Eminentia  arcnata,  42 

articular  is,  39 

capitata,  71 

cinerea,  265 

collateralis,  259,  260 

innominata,  36 
Epiblast,  17,  18 
Epididymis,  346 
Epiphysis,  20 

cerebri,  262 
Eustachian  tube,  43,  302 

valve,  205 
Eye,  297 

F. 

Fallopian  tubes,  351 
Fascia,  139 

anal,  150 

axillary,  154 

bucco-pharyngeal,  162 

Buck's,  149 

cervical,  157 

cremasteric,  148 


Fascia  dentata,  260 

iliac,  148 

infundibuliform,  148 

intercolumnar,  147 

lata,  186 

lumbar,  142 

masseteric,  171 

obturator,  150 

of  abdomen,  145,  148 

of  arm,  174 

of  breast,  154 

of  Colles,  149 

of  forearm,  176 

of  pelvis,  150 

of  Scarpa,  145 

palmar,  183 

parotid,  158 

perineal,  149 

plantar,  198 

prevertebral,  158 

recto- vesical,  150 

semilunar,  175 

subpubic,  149 

temporal,  172 

transversalis,  148 
Fasciculus  teres,  265 
Fat-pad,  buccal,  171 
Fissure,  calcarine,  256 

calloso-marginal,  256 

collateral,  257 

dentate,  256 

hippocampal,  256 

longitudinal,  257 

of  Glaser,  40 

of  Eolando,  255 

of  Sylvius,  255 

parietal,  62 

parieto-occipital,  257 

petro-squamous,  40 

precentral,255 

pterygo-maxillary,  58 

sphenoidal,  46,  57 

spheno-maxillary,  57 
Flocculus.  263 
Fontanelle,  62 
Foramen,  aortic,  153 

csecum,  39 

carotico-clinoid,  47 

carotico-tympanicus,  43 

centrale  cochleae,  42 

condylar,  36 

inferior  dental,  55 

infraorbital,  48,  49 

intervertebral,  24,  30    .; 


INDEX. 


365 


Foramen,  Jacobson's,  43 

jugular,  37 

lacerum,  59 

mastoid,  40 

mental,  54 

obturator,  77,  79 

of  Magendie,  253 

of  Monro,  259,  261 

of  Vesalius,  47 

optic,  44,  46,  57 

ovale,  46 

parietal,  37 

quadratum,  153 

rotundum,  45,  46 

sacral,  28 

singulare,  42 

spinosum,  46 

sternal,  32 

stylo-mastoid,  43 

supratrochlear,  69 

thyroid,  77,  79 
Foramina,  incisor,  49 

of  Scarpa,  49 

of  Stenson,  49 

Thebesii,  205 
Fornix,  261 
Fossa  acetabuli,  79 

anterior  palatine,  49,  58 

canine,  48 

condylar,  36 

coronoid,  69 

digastric,  40 

digital,  81 

glenoid,  40,  67 

guttural,  58 

hypo-trochanterica,  83 

iliac,  77 

incisor,  48,  54 

infraspinous,  66 

infratemporal,  58 

intercondylar,  82 
jugular,  43 

lachrymal,  38,  57 

mandibularis,  40 

myrtiform,  48 

nasal,  60,  308 

olecranon,  69 

ovalis,  205 

pituitary,  44 

pterygoid,  46 

radial,  69 
scaphoid,  46 

sigmoidea,  41 
spheno-maxillary,  58 


Fossa,  subarcuate,  42 

subscapular,  65 

supraspinous,  66 

temporal,  57 

trochlear,  38 

zygomatic,  58 
Funiculus  of  Eolando,  253 

cuneatus,  253 

gracilis,  253 

G. 

Galea  aponeurotica,  166 
Gall-bladder,  333 
Ganglion,  cervical,  292,  293 

Gasserian,  267 

geniculate,  272 

jugular,  274 

Meckel's,  269 

ophthalmic,  268 

otic,  271 

petrous,  274 

semilunar,  295 

submaxillary,  271 
Geniculate  bodies,  262 
Gerdy's  fibres,  183 
Glabella,  38 
Gland,  mammary,  352 

parotid,  321 

prostate,  342 

sublingual,  321 

submaxillary,  321 

thymus,  315 

thyroid,  315 
Groove,  basilar,  37 

bicipital,  68 

infraorbital,  49 

lachrymal,  49 

mylo-hyoid,  55 

obturator,  78 

olfactory,  48 

optic,  44 

posterior  palatine,  51 

spiral,  68 

subcostal,  33 
Gyrus,  angular,  256 

fornicatus,  257 

hippocampi,  257 

marginal,  256 

opertus,  256 

uncinate,  257 


H. 


Heart,  204 


366 


INDEX. 


Heiniarthrosis,  94 
Henle's  ankle-joint,  133 
classification  of  joints,  94 
vertebral  ligaments,  100 
wrist-joint,  114 
Hip-joint,  123 
Hippocampus,  259,  260 
Homologies,  muscular,  202 
of  carpus  and  tarsus,  92 
of  ilium  and  scapula,  92 
of  upper  and  lower  limbs,  91 
Hypoblast,  17, 18 
Hypophysis  cerebri,  258 


Ilio-tibial  band,  186 
Index,  humero-radial,  72 

of  cranium,  64 

sacral  29 
Infundibulum,  47,  258,  306 
Inion,  64 

Intervertebral  disks,  96 
Intestines,  324 
Iris  299 
Island  of  Reil,  256 


Joints,  classification  of,  93 


K. 


Kidney,  336 
Knee-joint,  125 


L, 


Labyrinth,  47,  305,  306 
Lacertus  fibrosus,  175 
Lambda,  63. 
Lamina  cinerea,  257 
cribrosa,  42 
papyracea,  47 
Larrey's  space,  153 
Larynx,  310 
Ligament  or  Ligaments,  accessory,  95 

of  astragalus,  135 

of  foregirm,  113 

of  hip,  154 

of  knee,  128 

of  tarsus,  136 

of  wrist,  116 

tibio-fibular,  134 


Ligament  or  Ligaments,  accessorium 
laterale,  103,  129 

mediale,  103,  129 

radiale,  119 

ulnare,  119 
acromio-clavicular,  106 
alar,  99,  127 
annular,  116,  194 
anterior,  95,  110,  114,  128,  132 
arcuate,  118,  121,  128,  153 
astragalo-scaphoid,  133 
atlo-axoid,  98 
Bertini,  124 
brachial,  174 
calcaneo-astragaloid,  133 
calcaneo-cuboid,  133,  136 
calcaneo-fibulare,  136 
calcaneo-naviculare,  136,  137 
calcaneo  scaphoid,  133,  136 
calcaneo-tibiale,  136 
capituli  fibulae,  131,  132 
capitulorum,  138 

dorsalia,  120 

volaria,  119 
capsular  of  elbow,  110 

of  hip,  123 

of  knee,  127 

of  lower  jaw,  103 

of  shoulder,  107 

of  vertebrae,  96 

of  wrist,  115 
carpi  commune,  116 

dorsale  profundum,  117 

volare  profundum,  118 
proprium,  117 
carpo-metacarpea,  117 
chondro-sternal,  101 
chondro-xiphoid,  102 
colli  costse,  101 
conjugal,  100 
conoid,  107 
coraco-acromial,  104 
coraco-clavicular,  107 
coraco-glenoidale,  109 
coraco-humeral,  109 
coronary,  126 
corruscans,  102 
costo-clavicular,  106 
costo-coracoid,  154 
costo-transverse,  100,  101 
costo- vertebral,  99,  100 
cotyloid,  123 
crucial,  98,  126,  194 
cuboideo-naviculare,  137 


INDEX. 


367 


Ligament    or    Ligaments,    cuneo-cu- 
boidea,  136 
deltoid,  132 
denticulatum,  249 
dorsal,  114,  119,  120,  133 
falciform,  122 
Flood's,  109 

fundiform  of  Retzius,  194 
Gimbernat's,  147 

reflected,  147 
<;lenoid,  108 
glenoideo-brachial,  109 
glenoideo-liumeral,  109 
hamo-metacarpeum,  119 
humero-coronoid,  111 
humero-olecrauon,  111 
iliacum  proprium,  120 
ilio-femorai,  124 
ilio-lumbar,  121 
ilio-pectiueal,  149 
ilio-trochanteric,  124 
inguinal,  147,  149 
interarticular,  100 

fibro-cartilage,  103,  106 
intercarpea,  117 
interchondral,  102 
interclavicular,  106 
intercostal,  102 
intercruralia,  101 
intermetacarpea,  117,  119 
intermetatarsea,  136,  137 
intermuscularia,  174 
interosseous,  113,  114,  132,  133 
interspinous,  96 
intersternal,  102 
intertransverse,  97 
intrajugular,  103 
ischio-capsular,  124 
iscliio-femoral,  124 
laciniatum,  194 

lateral,  99,  103,  111,  113,  129, 132 
latum,  99 
iumbo-costal,  101 
malleoli  lateralis,  134 
metatarsal,  133 
metatarso-phalangeal,  138. 
mucosum,  115,  127,  179 
naviculari  cuboidea,  136 
nuchse,  96 
oblique,  113,  128 
obturator,  98,  120 
occipito-atloid,  98,  99 
occipito-axoid,  99 
odontoid,  99 


Ligament    or    Ligaments    of    ankle- 
joint,  132 
of  Barkow,  111 
of  Bigelow,  124 
of  bladder,  150 
of  Burns,  187 
of  carpus,  114 
of  ilio-sacral  joint,  121 
of  Colles,  147 
of  elbow-joint,  110 
of  Hey,  187 
of  hip-joint,  123 
of  knee-joint,  125 
of  larynx,  311 
of  metacarpus,  114 
of  phalanges,  114,  133 
of  rectum,  150 
of  scapula,  104 
of  shoulder-joint,  107 
of  skull,  102 
of  tarsus,  132,  136 
of  uterus,  351 
of  Winslow,  128 
of  wrist-joint,  113 
of  Zinn,  170 
olecrano-coronoid,  111 
orbicular,  111,  124 
palmar,  114 
palpebral,  167 
patellae,  128 

petro-sphenoidal,  43,  103 
piso-hamatum,  119 
piso-metacarpeum,  119 
plantar,  133 

plicse  synov.  patellaris,  127 
popliteum  arcuatum,  128 
posterior,  95.  Ill,  114,  128,  132 
Poupart's,  146 
pterygo-maxillary,  104 
pterygo-petrosal,  103 
pubo-femoral,  124 
pubo-prostatic,  150 
radiate,  118 
radio-ulnar,  113 
retinacula  tendinum,  120 
retinaculum,  109 

lig.  arcuati,  128 

peronseorum,  194,  196 
sacro-coccygeum  articulare,  97 
sacro-sciatic,  122 
sacro-spinosum,  122 
sacro-tuberosum,  122 
scapho-cuboid,  133 
scapuloclavicular,  107 


368 


INDEX. 


Ligament  or   Ligaments,  Schlemm's, 
109 

semilunar  fibro-cartilages,  126 

spheno-maxillary,  104 

spino-glenoid,  105 

stellate,  99 

sterno-clavicular,  105 

stylo-hyoid,  104 

stylo-maxillary,  103 

stylo-myloid,  103 

subflava,  96,  179 

subpubic,  121 

suprascapular,  105 

supraspinous,  96 

suspensory  of  eye,  171 
of  penis,  145 

talo-calcanea,  135 

talo-cruralia,  135 

talo-fibulare,  135 

talo-naviculare,  136 

talo-tibiale,  135 

tarseum  transversum,  137 

tarso-metatarsea,  136 

teres,  123 

tibio-calcaneo-naviculare,  135 

tibio-fibular,  131,  134 

tibio-naviculare,  136 

transverse,   98,    105,    114,   119,    123, 
128,   132,   183 
humeral,  109 
of  pelvis,  150 

trapezoid,  107 

triangular  147,  149 
fibro-cartilage,  113 

tuberculi  costse,  101 

tuberositatum  vertebralium,  101 

vaginalia,  119,  120,  179 

vincula  tendinum,  179 
Ligula,  265 

Lingual  convolution,  257 
Lingula,  263 

mandibulse,  55 

sphenoidal  is,  44 
Limbus  sphenoidalis,  44 
Line,  buccal,-55 

gluteal,  77 

ilio-pectineal,  77 

intertrochanteric,  81 

oblique,  54,  71,  84,  85 

popliteal,  84 

spiral,  81 

temporal,  37 
Linea  alba,  146 

aspera,  81 


Linea  Douglasii,  147 

quadrati,  81 

semilunaris,  146 

Spigelii,  148 

splendens,  249 

transversa,  146 
Liver,  331 
Lobe,  central,  256 

frontal,  255 

occipital,  256 

parietal,  255 

temporo-sphenoidal,  256 
Locus  niger,  259 
Lungs,  316 
Lymphatic  glands,  axillary,  248 

cervical,  248 

inguinal,  245 

mesenteric,  246 

pelvic,  246 

thoracic,  247 
Lymphatics  of  lower  limb,  245 

of  abdomen,  246 

of  head  and  neck,  248 

of  pelvis,  246 

of  thorax,  247 

of  upper  limb,  247 

M. 

Malleolus,  84 

Mandible,  54 

Marrow,  21 

Meatus  of  nose,  48,  61 

Mediastinum,  316 

Medulla  oblongata,  253 

Membrana  sacciformis,  113 

tympani,  302 
Meniscus,  126 
Mesoblast,  17,  18 
Midriff,  152 
Modiolus,  305 
Mouth,  318 

Muscle  or   Muscles,  abductor  hallicis, 
199 

indicis,  185 

minimi  dig.,  184,  200 

ossis  metatarsi  quinti,  200 

pollicis,  182,  184 
accessorius,  179 
acromio-clavicularis,  173 
adductor  brevis,  193 

gracilis,  193 

hallicis,  200 

longus,  193 


INDEX. 


369 


Muscle  or  Muscles,  magnus,  193 

minimus,  193 

pollicis,  184 
agitator  caudse,  188 
amygdalo-glossus,  163 
anconeus,  176,  181 

quintus,  176 

epitrochlearis,  176 
anomalus,  169 

menti,  170 
articularis  genu,  191 
aryteno-epiglottic,  313 
arytenoideus,  314 
atlanto-mastoideus,  145 
auricularis,  166,  167 
azygos  pharyngis,  163 

iivuke,  163 
biceps,  174 

femoris,  192 
biveuter  cervicis,  143 

mandibulse,  158 
brachialis  anticus,  175 

internus,  175 
brachio-radialis,  180 
buccinator,  169 
bulbo-cavernosus,  152 
caninus,  168 
cephalo-pharyngeus,  162 
cervico-costo-humeralis,  160 
chondro-epitrochlearis,  154 
chondroglossus,  161 
ciliary,  299 
circumflexus,  163 
cleido-liyoideus,  159 
cleido-occipital,  158 
coccygeus,  151 
complexus,  143 
compressor  hemispli.  biilbi,  152 

naris,  169 

urethrse,  152 

venae  dorsalis  penis,  152 
constrictor  of  pharynx,  162 
coraco-brachialis,  175 
coraco-capsularis,  175 
coraco  minor,  175 
corrugator  supercilii,  167 
costo-coracoid,  141 
costo-fascialis,  160 
cremaster,  148 
crico-arytenoideus,  314 
crico-hyoideus,  160 
crico-thyroid,  313 
crureus,  191 
cubito-carpeus,  179 

24— Anat. 


Muscle  or  Muscles,  curvator  coccygis, 
151 
deltoid,  173 
depressor  alee  nasi,  169 
anguli  oris,  168 
labii  inferioris,  169 
septi,  169 
diaphragm,  152 
digastric,  159 
dilator  naris,  169 
dorso-epitrochlearis,  141,  176 
ejaculator  urinse,  152 
epicranius,  166 

temporalis,  166 
erector  penis,  151 

spinas,  142 
extensor  brevis  digit,  198 
digit,  manus,  182 
pollicis,  182 
carpi  rad.  access.,  180 
brevier,  180 
coccygis,  143 
intermedins,  180 
longior,  180 
ulnaris,  181 
communis  digit.,  180 
digiti  quinti,  181 
hallicis  brevis,  199 
indicis  proprius,  182 
longus  hallicis,  195 
digit.,  195 

primi  internodii  hall.,  195 
pollicis,  182 
medii  digiti,  182 
minimi  digiti,  181 
ossis  metac.  poll.,  182 
primi  interned,  poll.,  182 
sec.  intern,  poll.,  182 
flexor  brevis  digit.,  199 
accessorius,  199 
hall.,  200 

min.  dig.,  184,  200 
poll.,  184 
carpi  radialis,  177 
brevis,  179 
ulnaris,  17/ 
brevis,  179 
longus  digitorum,  197 
access.,  197 
hall.,  198 
pollicis,  179 
sublimis  digit.,  178 
profundus  digit.,  178 
frontalis,  166 


370 


INDEX. 


Muscle    or    Muscles,    gastrocuemius, 
196 
gemelli,  189 
genio-hyoglossus,  161 
genio-hyoideus,  160 
glosso-staphylinus,  163 
glutei,  188 
gluteo-perinealis,  151 
gracilis,  171,  193 
Horner's,  167 
hyoglossus,  161 
hyo-pharyngeus,  162 
hyo-thyroideus,  160 
iliacus,  187 

minor,  188 
ilio-costalis  cervicis,  143 

dorsi,  143 

lumborum,  143 
ilio-psoas,  187 
incisivi,  169 
indicator,  182 
infraspinatus,  173 
interclavicular,  154 
intercostales,  156 
interossei,  185,  200 
interspinales,  144 
intertransversales,  144 
intertransversarii,  165 
ischio-aponeuroticus,  193 
ischio  cavern osus,  151,  152 
ischio-coccygeus,  151 
labii  proprius,  169 
laryngo-pharyngeus,  162 
latissimus  dorsi,  140 

anguli  oris,  168 

labii  sup.,  168 
levator  ani,  151 

claviculse,  158 

menti,  170 

palati,  163 

palpebral,  170 

scapulae,  165 
levatores  costarum,  144 
lingualis,  161 
longissimus  capitis,  143 

cervicis,  143 

dorsi,  143 
longus  atlantis,  165 

capitis,  165 

colli,  165 
lumbricales,  183,  199 
malaris,  167 
masseter,  171 
mental  is,  170 


Muscle  or  Muscles,  mento-liyoid,  158 
multifidus,  144 
myloglossus,  161 
mylohyoideus,  160 
nasalis,  169 
naso-labialis,  169 
oblique,  inferior,  170 

superior,  170 
obliquus  capitis,  144 

externus,  146 

internus,  147 
obturator,  189 
occipitalis,  166 

minor,  157 
occipito-frontalis,  166 
occipito-pharyngeus,  163 
occipito-scapularis,  140 
of  abdomen,  145 
of  arm,  174 
of  back,  139 
of  breast,  154 
of  foot,  198 
of  forearm,  176 
of  hand,  183 
of  head,  166 
of  hip,  187 
of  hyoid  bone,  158 
of  leg,  195 
of  neck,  157 
of  orbit,  170 
of  palate,  163 
of  perineum,  150 
of  pharynx,  162 
of  scapula,  173 
of  thigh,  190 
of  tongue,  161 
of  trunk,  139 
omo-hyoideus,  159 
opponens  hallicis,  200 

minimi  dig.,  185,  200 

pollicis,  184 
orbicularis  oculi,  167 

oris,  169 
palato-glossus,  163 
palato-pharyngeus,  163 
palato-staphylinus,  163 
palmaris  brevis,  183 

longus,  177 
papillares,  206 
pectinati,  205 
pectineus,  193 
pectoralis  major,  154 

minor,  155 

minimus,  155 


INDEX. 


371 


Muscle  or  Muscles,  peroneo-calcaneus, 
198 
peroneo-tibialis,  197 
peroneus  access.,  196 

brevis,  196 

longus,  195 

quartus,  196 

quint,  digiti,  196 

tertius,  195 
petro-pharyngeus,  163 
petro-staphylinus,  163 
pharyngo-mastoideus,  163 
pharyngo-staphylinus,  163 
pisi-annularis,  185 
pisi-metacarpeus,  185 
pisi-uncinatus,  185 
plantaris,  197 
platysma  myoides,  157 
popliteus,  197 

minor,  197 
pronator  quadratus,  179 

teres,  177 
psoas  magnus,  188 

parvus,  188 
pterygoideus,  172 

proprius,  172 
pterygo-pharyngeus,  163 
pterygo-spinosus,  172 
pubo-coccygeus,  151 
pubo-transversalis,  148 
pyramidal  is,  146 

nasi,  169 
pyriformis,  189 
quadratus  femoris,  189 

labii  sup.,  168 

lumborum,  187 

menti,  169 

plan  tee,  199 
quadriceps  femoris,  190 
radialis  internus,  177 
radio-carpeus,  179 
recti  of  eye,  170 
rectus  abdominis,  145 

capitis  anticus,  165 
lateralis,  145 
posticus,  144 

femoris,  191 

lateralis  abd.,  146 
rhombo-atloideus,  141 
rhomboid eus  major,  140 

minor,  140 

occipitalis,  140 
risorius,  168 
rotatores,  144 


Muscle   or    Muscles,   sacro-coccygeus, 
143,  151 
sacro-lumbalis,  142 
sacro-spinalis,  142 
sartorius,  190 
scaleni,  164 
scalenus  minimus,  165 

pleuralis,  165 
semimembranosus,  192 
semispinal  es,  143 
semitendinosus,  192 
serratus  anticus,  155 

magnus,  155 

posticus,  141 
soleus,  196 

spheno-pbaryngeus,  163 
spheno-staphylinus,  163 
sphincter  ani,  151 

oris,  169 
spinales,  143 
splenius,  141 

capitis  access.,  141 

colli  access.,  141 
stapedius,  304 
sternalis  iDrutorum,  154 
sterno-clavicularis,  154 
sterno-cleido-mastoid,  158 
sterno-hyoideus,  159 
sterno-scapularis,  154 
sterno-thyreoideus,  160 
stylo-auricularis,  161 
stylo-glossus,  161 
stylo-hyoideus,  159 

alter,  159 

profundus,  159 
stylo-pharyngeus,  162 
subanconeus,  176 
subclavius,  154 
subcruralis,  191 
subcutaneus  colli,  157 
subdeltoid,  173 
subscapularis,  174 

minor,  174 
supinator  brevis,  182 

longus,  180 
access.,  180 
supraclavicularis,  154 

proprius,  158 
supracostalis,  156 
supraspinatus,  173 
temporal,  172 

minor,  172 
tensor  palati,  163 

tarsi,  167 


372 


INDEX. 


Muscle   or  Muscles,  tensor   trochlese, 
171 

tympani,  304 

vaginse  femoris,  190 
teres  major,  140 

minor,  173 
thyreo-hyoideus,  160 
tliyro-arytenoid,  313 
thyro-epiglottic,  313 
tibialis  anticus,  194 

posticus,  197 

secundus,  197 
tibio-fascialis,  195 
trachelo-mastoid,  143 
transversalis  abd.,  148 

cervicis,  143,  165 
transversi  thoracis,  156 
transverso-spinalis,  143 
transversus  colli,  160 

menti,  168 

nuchse,  158 

orbitse,  171 

pedis,  200 

perinei,  151 
profundus,  152 
trapezius,  139 
triangularis  menti,  168 

sterni,  156 
triceps,  175 

surse,  196 
triticeo-glossus,  161 
trochlearis,  170 
ulnaris  extern  us,  181 

internus,  177 

brevis,  179 

quinti  digiti,  181 
ulno-carpeus,  179 
vasti,  191 
zvgomaticus,  168 
Myology,  19,  138 

isr. 

Nasion,  63 

Nerve  or  Nerves,  abducens,  271 

anterior  crural,  286 

Arnold's,  275 

auditory,  273 

auricularis  magnus,  279 

auriculo-temporal,  270 

cardiac,  276,  293 

chorda  tympani,  272,  304 

ciliary,  268 

circumflex,  281 


Nerve  or  Nerves,  communicans  noni, 
279 
cranial,  266 
descendens  noni,  277 
dorsal,  283 
facial,  272 
genito-crural,  285 
glosso-pharyngeal,  273 
gluteal,  288 
gustatory,  271 
hypoglossal,  277 
ilio-hypogastric,  285 
ilio-inguinal,  285 
inferior  maxillary,  270 
infraorbital,  269 
interosseous,  282,  283 
Jacobson's,  274,  304 
laryngeal,  275 
lingual,  271,274 
lumbar,  283 
median,  281 
motor  oculi,  267 
musculo-cutaneous,  281,  291 
musculo-spiral,  283 
nasal,  268,  269 
obturator,  286 
occipitalis  minor,  279 
olfactory,  266 
ophthalmic,  267 
optic,  266 
orbital,  269 
pathetic,  267 
perineal,  289 
peroneal,  291 
petrosal,  270,  272,  274 
pharyngeal,  270,  275 
phrenic,  279 
plantar,  290 
pneumogastric,  274 
popliteal,  289,  291 
pudic,  289 
radial,  283 
saphenous,  287 
sciatic,  288,  289 
spinal  accessory,  276 
splanchnic,  294 
suboccipital,  277 
superficialis  colli,  279 
superior  maxillary,  269 
suprascapular,  280 
sympathetic,  292 
thoracic,  280 
tibial,  290,  291 
trifacial,  267 


INDEX. 


373 


Nerve  or  Nerves,  tympanic,  272,  274 

ulnar,  282 

Vidian,  270 
Neural  arch,  24 
Neuroglia,  251 
Neurology,  19,  249 
Nose,  307 
Notch,  coraco-scapular,  67 

cotyloid,  79 

episternal,  32 

ethmoidal,  38 

great  scapular,  66 

iliac,  77 

ilio-sciatic,  78 

intercondylar,  82 

jugular,  37 

lachrymal,  49 

nasal  38,  48 

parietal,  40 

popliteal,  84 

pterygoid,  48 

sciatic,  77,  79,  122 

semilunar,  32,  55 

sigmoid,  55 

spheno-palatine,  52 

suprascapular,  67 

vertebral,  24 
Notochord,  17 
Nucleus  amygdalae,  260 

caudate,  260 

lenticular,  260 

o. 

Obelion,  63 
Obex,  265 
Occipital  point,  63 
CEsophagus,  322 
Olecranon,  70 
Olfactory  tract,  258 
Olivary  body,  253 
Omentum,  341 
Operculum,  256 
Ophryon,  63 
Opisthion,  64 
Optic  commissure,  258,  266 

thalamus,  261 

tract,  258,  266 
Orbital  plate,  38,  45,  47 
Orbits,  57 
Organ  of  Corti,  307 
Os  acetabuli,  79 

capitatum,  74 

central e,  75 


Os  coxa3,  76 

innominatum,  76 

planum,  47 

pubis,  78 

trigonum,  88 
Ossa  supersternalia,  32 

fcriquetra,  56 
Ossiculum  jugulare,  56 
Ossification,  20 
Osteology,  19 
Ovary,  351 


Palate,  320 
Palatine  trigone,  49 
Pancreas,  324 
Panniculus  adiposus,  139 

carnosus,  139 
Parietal  boss,  37 
Parovarium,  352 
Pars  intermedia,  272 
Patella,  83 

Peduncles  of  cerebellum,  263 
Pelvic  girdle,  91,  120 
Pelvis,  76,  79 

position  of,  80 

difierences  in,  80 
Penis,  342 
Pericardium,  204 
Perimysium,  138 
Periosteum,  20 
Peritoneum,  339 
Pes  accessorius,  259,  260 

hippocampi,  260 
Phalanges,  76,  89 
Pharynx,  322 
Pia  mater,  249,  252 
Pillar  of  fauces,  163 
Pineal  gland,  262 
Pituitary  body,  258 
Pleura,  315 
Plexus,  brachial,  280 
•  cardiac,  294 

carotid,  292 

cavernous,  292 

cervical,  278 

epigastric,  295 

lumbar,  284 

pelvic,  296 

sacral,  288 
Pons  Varolii,  254 
Porus  acusticus,  42 
Posterior  nares,  59 


374 


INDEX. 


Precuneus,  257 
Primitive  streak,  17, 18 
Process,  accessory,  27 

alveolar,  49 

angular,  38 

articular,  24,  31 

clinoid,  44,  45 

cochleariform,  43 

coracoid,  66 

coronoid,  55,  70 

ensiform,  32 

ethmoidal,  54 

frontal,  52 

liamular,  46,  54 

incisor,  50 

intrajugular,  37 

jugular,  36 

lachrymal,  54 

malar,  49 

mammillary,  27 

marginal,  53 

mastoid,  40 

maxillary,  51,  54 

nasal,  38,  49 

odontoid,  25 

orbital,  51,  53 

palate,  49 

paramastoid,  37 

petrosal,  44 

pyramidal,  51 

sphenoidal,  51 

spinous,  24,  30,  45 

styloid,  43,  71,  72,  75,  85 

superior  turbinate,  48 

supracondylar,  69 

transverse,  24,  30 

tubarius,  46 

uncinate,  47,  74 

ungual,  76 

vaginal,  43,  44,  46 

xiphoid,  32 
Processes  of  Ingrassias,  45 

pterygoid,  44,  46 
Pyramid,  253 

R. 

Eadio-carpal  joint,  115 
Kadius,  71 

Eeceptaculum  chvli,  245 
Eectum,  329 
EeStiform  body,  253 
Eetina,  299 
Eibs,  vertebro-sternal,  32 


Eibs,  vertebro-chondral,  32 

vertebral,  32 
Eidge,  gluteal,  81 

mylo-hyoid,  55 

pectoral,  68 

pronator,  71 

superciliary,  38 

supinator,  68,  70 

supracondylar,  68,  81 
Eing,  abdominal,  146,  149 

crural,  187 

femoral,  149 
Eostrum,  45,  259 

S. 

Saccus  endolymphaticus,  42 
Sacrum,  28 
Sagittal  plane,  19 
Saphenous  opening,  187 
Sarcolemma,  138 
Scapula,  65 
Scarpa's  triangle,  229 
Sclerotic  coat,  298 
Scrotum,  345 
Segmentation  sphere,  17 
Sella  turcica,  44 
Semilunar  valves,  206 
Septum  crurale,  187 

lucidum,  259,  261 

nasi,  60 

tubse,  43 
Sesamoid  plate,  138 
Sheath,  crural,  187 

of  rectus,  147 
Shoulder,  64 
Shoulder-girdle,  90,  104 
Shoulder-joint,  107 
Sigmoid  cavity,  70,  72 
Sinus,  cavernous,  238,  271 

circular,  238 

coronary,  233 

frontal,  38 

lateral,  238 

longitudinal,  238 

magnus,  209 

maxillary,  50 

occipital,  238 

petrosal,  238 

straight,  238 

transverse,  239 
Skeleton,  19 
Skull,  as  a  whole,  55 

fixed  points  on,  63 


INDEX. 


375 


Somatopleure,  18 
Spermatic  cord,  344 
Spheno-ethmoidal  recess,  61 
Spheno-petrosal  lamina,  47 
Spinal  cord,  249 
Spine,  44 

iliac,  79 

nasal,  48,  51 

of  ischium,  77 

of  pubis,  77 

of  scapula,  66 

of  tibia,  84 

palatine,  51 

peroneal,  8^ 
Spines,  mental,  54 
Splanchnology,  19,  310 
Splanchnopleure,  18 
Spleen,  335 
Splenium,  259 
Stapes,  303 
Stephanion,  64 
Sternum,  31 
Stomach,  323 
Striae  acousticse,  265 
Subnasal  point,  63 
Substantia  ferruginea,  266 

gelatinosa,  251 
Sulci  of  brain,  255 
Sulcus,  frontal,  39 

^occipitalis,  41 

preauricular,  79 

pulmonalis,  34 
Superior  maxilla,  48 
Supination,  112,  131 
Suprarenal  capsule,  335 
Sustentaculum  tali,  86 
Sutures,  coronal,  56 

lambdoid,  56 

sagittal,  56 
Symphysis  pubis,  78,  120 
Synarthrodia!  joints,  93 
Synchondrosis,  94 
Syndesmosis,  94 
Synovial  cavities  of  ankle,  137 
of  wrist,  116 

membrane,  93 

T. 

Taenia  semicircularis-,  260 

Talus,  86 

Tarsus,  86 

Teeth,  318 

Tegmen  tympani,  40,  42 


Tegmentum,  259 
Tendo  Achillis,  197 

oculi,  167 
Tentorium,  252 
Testis,  344 
Thigh,  80 
Thorax,  31,  34 
Tibia,  83 
Tongue,  309 
Tonsil,  263,  320 
Torcular  Herophili,  36 
Torus  occipitalis  transversus,  37 
Trachea,  314 

Tractus  spiralis  foraminulentus,  42 
Tragus,  301 
Trapezium,  254 
Triangle  of  Petit,  147 

suboccipital,  145 
Trochanters,  81 
Trochlea,  69 
Tuber  annulare,  254 
]      cinereum,  258 

olfactorium,  258 
Tubercle,  adductor,  82 

carotid,  26 

Chassaignac's,  26 

conoid,  65 

deltoid,  65 

infraglenoid,  67 

lachrymal,  49 

Lisfranc's  33 

mental,  54 

obturator,  78 

of  femur,  81 

of  radius,  72 

of  the  quadratus,  81 

of  tibia,  84 

pharyngeal,  37 

pterygoid,  46 

scalene,  33 

supraglenoid,  67 
Tubercles  of  astragalus,  87 
Tuberosity,  bicipital,  71 

costal,  65 

great,  68 

iliac,  77 

of  ischium,  78,  79 

of  scaphoid,  73,  87 
small,  68 

of  superior  maxilla,  48 

of  the  palate-bone,  51 

of  tibia,  83 

of  trapezium,  74 

of  ulna,  70 


376 


INDEX. 


Tuberosity,  pubo-ischiatic,  78 
Tympanic  plate,  44 
Tympanum,  301 


u. 


Ulna,  70 
Ureter,  337 
Urethra,  343,  349 
Uterus,  349 


Vagina,  349 

Valve  of  Vieusseus,  263,  265 

Vas  deferens,  347 

Vein  or  Veins,  angular,  235 

axillary,  240 

azygos,  240,  241 

basilic,  240 

cardiac,  233 

cava  inferior,  241 
superior,  233 

cephalic,  240 

cerebellar,  237 

cerebral,  237 

cervical,  234 

coronary,  233 

corporis  striati,  237 

diploic,  239 

emissary,  239 

facial,  235 

femoral,  243 

hepatic.  242 

iliac,  242,  243 

innominate,  234 

intercostal,  235 

internal  maxillary,  236 

jugular,  236,  237 

lumbar,  241 

magna  Galeni,  237 

median,  240 

oblique  of  Marshall,  233 

ophthalmic,  239 


Vein  or  Veins,  popliteal,  243 

portse,  244 

pudic,  243  . 

pulmonary,  233 

renal,  242 

saphenous,  242 

spermatic,  242 

spinal,  241 

subclavian,  240 

systemic,  233 

temporal,  236 

temporo-maxillary,  235 

thyroid,  234 

tibial,  243 

ulnar,  240 

vertebral,  234 
Velum  interpositum,  261 

medullary,  263,  265 

palati,  163 
Ventricles,  205 

of  brain,  259,  262,  263 
Vertebra  dentata,  25 

prominens,  25 
Vertebrse,  cervical,  24 

characteristics  of,  23 

dorsal,  26 

false,  28 

lumbar,  26,  27 

sacral,  28 
Vertebral,  25 

column,  23,  29 
Vestibule,  305 
Vincula  tendinum,  179 
Vitelline  membrane,  17 
Vocal  cords,  312 
Vulva,  348 

w. 

"White  line,"  150 
Wings  of  sphenoid,  44,  45 
Wrist-bones,  72 
Wrist-joint,  113 


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actually  engaged  in  the  teaching  of  the  pri- 
mary subjects  can  be  fully  aware  of  the  diffi- 
culties encountered  by  students  who  attempt 
the  study  of  these  subjects  without  a  knowl- 
edge of  either  physics  or  chemistry.  These 
are  especially  felt  by  the  teacher  of  physi- 
ology. It  is,  however,  impossible  for  him  to 
impart  a  knowledge  of  the  main  facts  of  his 
subject  and  establish  them  by  reasons  and 
experimental  demonstrations,  and  at  the 
same  time  undertake  to  teach  ab  initio  the 
principles  of  chemistry  or  physics.  Hence 
the  desirability,  we  may  say  the  necessity, 
for  some  such  work  as  the  present  one. — The 
Montreal  Medical  Journal,  July,  1890. 


No  man  in  America  was  better  fitted  than 
Dr.  Draper  for  the  task  he  undertook,  atd 
he  has  provided  the  student  and  practitioner 
of  medicine  with  a  volume  at  once  readable 
and  thorough.  Even  to  the  student  who  has 
some  knowledge  of  physics  this  book  is  use- 
ful, as  it  shows  him  its  applications  to  the 
profession  that  he  has  chosen.  Dr.  Draper, 
as  an  old  teacher,  knew  well  the  difficulties 
to  be  encountered  in  bringing  his  subject 
within  the  grasp  of  the  average  student,  and 
that  he  has  succeeded  so  well  proves  once 
more  that  the  man  to  write  for  and  examine 
students  is  the  one  who  has  taught  and  is 
teaching  them.  The  book  is  well  printed 
and  fully  illustrated,  and  in  every  way  de- 
serves grateful  recognition. 

While  all    enlightened   physicians   will 


Power's  Physiology. 

HUMAN  PHYSIOLOGY.  By  Henry  Power,  M.B.,  F.R.C.S., 
Examiner  in  Physiology,  Royal  College  of  Surgeons  of  England.  Second 
edition.  In  one  12mo.  volume  of  509  pages,  with  68  illustrations.  Cloth, 
11.50.     See  Students^  Series  of  Manuals^  at  end. 

Robertson's  Physiological  Physics. 

PHYSIOLOGICAL  PHYSICS.  By  J.  McGregor  Robertson, 
M.  A.,  M.  B.,  Muirhead  Demonstrator  of  Physiology,  University  of  Glas- 
gow. In  one  12mo.  volume  of  537  pages,  with  219  illustrations.  Limp 
cloth,  $2.00.     See  Students''  Series  of  Ilanuals,  at  end. 


Bell's  Comparative  Anatomy  and  Physiology. 

COMPARATIVE  ANATOMY  AND  PHYSIOLOGY.     By 

F.  Jeffrey  Bell,  M.  A.,  Professor  of  Comparative  Anatomy  at  King's 
College,  London.  In  one  12mo.  volume  of  561  pages,  with  229  illustrations. 
Limp  cloth,  |2.00.     See  Students^  Series  of  3Ianu(ds,  at  end. 


LEA  BROTHERS  &  CO.,  70S,  708  &  7t0  Sansom  Street,  Philadelphia, 


^  Ph\?siolog\? — (Continued).  v 

Foster's  Physiology— New  American  Edition. 

TEXT  BOOK  OF  PHYSIOLOGY.  By  Michael  Foster,  M.D., 
F  R  S.,  Prelector  in  Physiology  and  Fellow  of  Trinity  College,  Cambridge, 
England.  New  (fourth)  and  enlarged  American  from  the  fifth  and  revised 
English  edition,  with  notes  and  additions.  In  one  handsome  octavo  volume 
of  1072  pages,  with  282  illustrations.     Cloth,  $4.50;  leather,  |5.50. 


The  appearance  of  another  edition  of 
Foster'r  Physiology  again  reminds  us  of  the 
continued  popularity  of  this  most  excellent 
work  There  can  be  no  doubt  that  this  text- 
book not  only  continues  to  lead  all  others  in 
the  English  language,  but  that  this  last  edi- 
tion is  superior  to  its  predecessors.  Every 
page  bears  evidences  of  careful  revision. 
Although  the  work  of  the  American  editor 
in  former  editions  has  been  by  the  author 
largely  adopted  in  a  modified  form  in  this 
revision,  much  was  still  left  to  be  done  by 
the  editor  to  render  the  work  fully  adapted 
to  the  wants  of  our  American  students,  so 
that  the  American  edition  will  undoubtedly 


continue  to  supply  the  market  on  this  side 
of  the  Atlantic.  The  work  has  been  pub- 
lished in  the  characteristic  creditable  style 
of  the  Leas,  and  owing  to  its  enormous  sale 
is  offered  at  an  extremely  low  price. — The 
Medical  and  Surgical  Reporter ^  January  9,'52. 
Foster's  Physiology  would  probably  be 
placed  by  universal  verdict  at  the  head  of 
all  works  of  its  class  that  the  English-speak- 
ing  world  has  yet  produced.  It  appears  to 
be  a  complete  storehouse  of  physiological 
lore.  The  work  is  deserving  of  unstinted 
praise. — American  Practitioner  and  I^ews, 
March  12, 1892. 


Dallon's  Pliysiology— Seventh  Edition. 

A  TREATISE  ON  HUMAN  PHYSIOLOGY.  Designed  for 
the  Use  of  Students  and  Practitioners  of  Medicine.  By  John  C.  Dalton, 
M.D.,  Professor  of  Physiology  in  the  College  of  Physicians  and  Surgeons, 
New  York.  Seventh  edition,  thoroughly  revised.  In  one  octavo  volume  of 
722  pages,  with  252  engravings.     Cloth,  |5.00;  leather,  |6.00. 

From  the  first  appearance  of  the  book  it 
has  been  a  favorite,  owing  as  well  to  the 
author's  renown  as  an  oral  teacher  as  to  the 


charm  of  simplicity  with  which,  as  a  writer^ 
he  always  succeeds  in  investing  even  intri- 
cate subjects.  It  must  be  gratifying  to  him 
to  observe  the  frequency  with  which  his 
work,  written  for  students  and  practitioners, 


is  quoted  by  other  writers  on  physiology. 
This  fact  attests  its  value,  and,  in  great 
measure,  its  originality.  It  now  needs  no 
such  seal  of  approbation,  however,  for  the 
thousands  who  have  studied  it  in  its  various 
editions  have  never  been  in  any  doubt  as  to 
its  sterling  worth. — New  York  Medical  JouT' 
naU  October,  1882. 


Chapman's  Physiology. 


A  TREATISE  ON  HUMAN  PHYSIOLOGY.  By  Henry  C. 
Chapman,  M.  D.,  Professor  of  Institutes  of  Medicine  and  Medical  Juris- 
prudence in  Jefferson  Medical  College  of  Philadelphia.  In  one  octavo  vol- 
ume of  925  pages,  with  605  engravings.    Cloth,  |5.50;  leather,  $6.50. 


Matters  which  have  a  practical  bearing 
on  the  practice  of  medicine  are  lucidly  ex- 
pressed ;  technical  matters  are  given  in  min- 
iitedetail;  elaborate  directions  are  stated  for 
the  guidance  of  students  in  the  laboratory. 


In  every  respect  the  work  fulfils  its  promise, 
whether  as  a  complete  treatise  for  the  stu- 
dent or  for  the  physician;  for  the  former  it 
is  so  complete  that  he  need  look  no  farther. 
—North  Carolina  Medical  Journal^  Nov.  1887, 


The  Students'  Quiz  Series— fhysioloot,  $i.  see  f. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


CheinistrxJ. 


Bloxam's  Chemistry— Fifth  Edition. 


CHEMISTRY,  INORGANIC  AND  ORGANIC.  By  Charles 
L.  Bloxaini,  Professor  of  Chemistry  in  King's  College,  London.  New 
American  from  the  fifth  London  edition,  thoroughly  revised  and  much  im- 
proved. In  one  very  handsome  octavo  volume  of  727  pages,  with  292  illus- 
trations.   Cloth,  $2.00;  leather,  $3.00. 


We  know  of  no  treatise  on  chemistry 
which  contains  so  much  practical  informa- 
tion in  the  same  number  of  pages.  The 
book  can  be  readily  adapted  not  only  to  the 
needs  of  those  who  desire  a  tolerably  com- 
plete course  of  chemistry,  but  also  to  the 


needs  of  those  who  desire  only  a  general 
knowledge  of  the  subject.  It  is  both  a  satis- 
factory text-book,  and  a  useful  book  of  refer- 
ence.— Boston  Medical  and  Surgical  Journal^ 
June  19, 1884. 


Frankland  &  Japp's  Inorganic  Chemistry. 

INORGANIC  CHEMISTRY.  By  E.  Frankland,  D.  C.  L., 
F.  R.  S.,  Professor  of  Chemistry  in  the  Normal  School  of  Science,  London, 
and  F.  R.  Japp,  F.  I.  C,  Assistant  Professor  of  Chemistry  in  the  Normal 
School  of  Science,  London.  In  one  handsome  octavo  volume  of  677  pages 
with  51  woodcuts  and  2  plates.     Cloth,  |3.75;  leather,  |4.75. 


This  work  should  supersede  other  works 
of  its  class  in  the  medical  colleges.  It  is  cer- 
tainly better  adapted  than  any  work  upon 
chemistry,  with  which  we  are  acquainted,  to 
impart  that  clear  and  full  knowledge  of  the 
science  which  students  of  medicine  should 


have.  Physicians  who  feel  that  their  chem- 
ical knowledge  is  behind  the  times,  would 
do  well  to  study  this  work.  The  descriptions 
aud  demonstrations  are  made  so  plain  that 
there  is  no  difficulty  in  understanding  them. 
— Cincinnati  Medical  News,  January,  1886, 


Luff's  Manual  of  Chemistry— Just  Ready. 

A  MANUAL  OF  CHEMISTRY.  For  the  Use  of  Students  of 
Medicine.  By  Arthur  P.  Luff,  M.  D.,  B.  Sc,  Lecturer  on  Medical  Juris- 
prudence and  Toxicological  Chemistry,  St.  Mary^s  Hospital  Medical  School, 
London.  In  one  12mo.  volume  of  522  pages,  with  36  engravings.  Cloth, 
12.00.     See  Students^  Series  of  Manuals^  at  end. 


Greene's  Medical  Chemistry. 


A  MANUAL  OF  MEDICAL  CHEMISTRY.    For  the  Use  of 

Students.  Based  upon  Bowman's  Medical  Chemistry.  By  William  H. 
Gbeene,  M.  D.,  Demonstrator  of  Chemistry  in  the  Medical  Department  of 
the  University  of  Pennsylvania.  In  one  12mo.  volume  of  310  pages,  with 
74  illustrations.     Cloth,  |1.75. 


LEA  BROTHERS  &  CO,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Chemistr\? — (Continued). 

Simon's  Manual  of  Chemistry— New  (4th)  Edition. 

MANUAL  OF  CHEMISTRY.  A  Guide  to  Lectures  and  Lab- 
oratory Work  for  Beginners  in  Chemistry.  A  Text-book,  specially  adapted 
for  Students  of  Pharmacy  and  Medicine.  By  W.  Simon,  Ph.  D.,  M.  D., 
Prof,  of  Chemistry  in  the  College  of  Physicians  and  Surgeons,  Baltimore, 
Professor  of  Chem.  in  the  Md.  College  of  Pharm.  New  (fourth)  edition.  In 
one  8vo.  volume  of  about  500  pages,  with  44  woodcuts  and  7  colored  plates 
illustrating  56  of  the  most  important  chemical  tests.  Cloth,  |3. 25.  Just  Ready. 
A  notice  of  the  previous  edition  is  appended. 


While  possessing  all  the  usual  qualities  of 
an  excellent  text-book  for  the  student  or 
laboratory,  this  Manual  presents  the 
unique  advantage  of  furnishing  plates  show- 
ing the  variously  shaded  colors  of  certain 
ehomicals,  etc.,  and  their  reactions.    This 


Chemistry  is  especially  valuable  to  medi- 
cal students  and  practitioners,  as  devoting 
so  much  of  detail  to  descriptions  of  analyses, 
tests,  etc.,  of  those  things  with  which  the 
doctor  has  mostly  to  deal. —  Virginia  Medical 
Monthly^  January,  1892. 


Attfield's  Chemistry— Twelfth  Edition. 

CHEMISTRY,  GENERAL,   MEDICAL  AND  PHARMA- 

ceutical ;  Including  the  Chemistry  of  the  U.  S.  Pharmacopoeia.  A  Manual 
of  the  General  Principles  of  the  Science,  and  their  Application  to  Medicine 
and  Pharmacy.  By  Johit  Attfield,  M.  A.,  Ph.D.,  Prof  of  Practical 
Chemistry  to  the  Pharm.  Soc.  of  Great  Britain.  A  new  American,  from 
the  12th  English  edition,  specially  revised  by  the  author  for  America.  In 
one  12mo.  volume  of  782  pages,  with  88  illus.     Cloth,  $2.75;  leather,  $3.25. 

out.  His  book  is  precisely  what  the  title 
claims  for  it.  The  admirable  arrangement 
of  the  text  enables  a  reader  to  get  a  good 
idea  of  chemistry  without  the  aid  of  experi- 
ments, and  again  it  is  a  good  laboratory  guid6 
and  finally  it  contains  such  a  mass  of  well- 
arranged  information  that  it  will  always 
serve  as  a  handy  book  of  reference.  This  last 
edi  tion  shows  the  marks  of  the  latest  progress 
made  in  chemistry  and  chemical  teaching. — 
New  Orleans  Med.  &  Surg.  Jour.j  Nov.  1889. 


Attfield's  Chemistry  is  the  most  popular 
book  among  students  of  medicine  and 
pharmacy.  This  popularity  has  a  good, 
substantial  basis.  It  rests  upon  real  merits. 
Attfield's  work  combines  in  the  happiest 
manner  a  clear  exposition  of  the  theory  of 
chemistry  with  the  practical  application  of 
this  knowledge  to  the  everyday  dealings  of 
the  physician  and  pharmacist.  His  discern- 
ment is  shown  not  only  in  what  he  puts 
into  his  work,  but  also  in  what  he  leaves 


Fownes'  Chemistry— Twelfth  Edition. 


A  MANUAL  OF  ELEMENTARY  CHEMISTRY;  Theo- 
retical and  Practical.  By  George  Fownes,  Ph.  D.  Embodying  Watts^ 
Physical  and  Inorganic  Chemistry.  New  American,  from  the  twelfth  English 
edition.  In  one  large  royal  12mo.  volume  of  1061  pages,  with  168  illustra- 
tions on  wood  and  a  colored  plate.     Cloth,  $2.75;  leather,  $3.25. 

Of  all  the  works  on  chemistry  intended  for 
the  use  of  medical  students,  Fownes'  Chem- 
istry is  perhaps  the  most  widely  used.    Its 


popularity  is  based  upon  its' excellence. 
This  last  edition  contains  all  of  the  material 
found  in  the  previous,  and  it  is  also  enriched 
by  the  addition  of  Watts'  Physical  and  In- 


organic Chemistry.  All  of  the  matter  is 
brought  to  the  present  standpoint  of  chem- 
ical knowledge.  We  may  safely  predict 
for  this  work  a  continuance  of  the  fame  and 
favor  it  enjoys  among  medical  students. — 
New  Orleans  Medical  and  Surgical  Journal ^ 
March,  1886. 


The  Students'  Quiz  Series— Chemistry,  $1.  See  P.  1. 

LEA  BROTHERS  &  CO..  706,  708  <£  710  Sansom  Street.  Philadelphia. 


Chemistrxp— (Continued). 


Remsen's  Theoretical  Chemistry— new  (4th)  edition. 

PRINCIPLES  OF  THEORETICAL  CHEMISTRY,  with 
special  reference  to  the  Constitution  of  Chemical  Compounds.  By  Ira 
Eemsen,  M.  D.,  Ph.  D.,  Professor  of  Chemistry  in  the  Johns  Hopkins  Uni- 
versity, Baltimore.  Fourth  and  thoroughly  revised  edition.  In  one  hand- 
some royal  12mo.  volume  of  325  pages.     Cloth,  $2.00.    Just  ready. 

No  comment  need  be  made  on  the  excel- 
lence of  this  work.  As  a  guide  to  the  study  of 
'J'heoietiealGheniistry  it  remains  unequalled, 


The  favor  which  has  been  shown  preceding 
editions  of  the  work  is  sufficient  proof  that 
the  object  of  the  author  in  enabling  students 
to  obtain  clear  ideas  in  regard  to  the  funda- 
mental principles  of  chemistry  has  been  suc- 


cessfully accomplished.  Since  the  publica- 
tion of  the  last  edition  in  1887,  the  work  has 
been  translated  into  German  and  into  Italian 
—certainly  no  greater  compliment  could  be 
desired  by  any  author.  The  work  will  con- 
tinue deservedly  to  hold  the  fi  rst  place  among 
the  numerous  treatises  on  Theoretical  Chem- 
istry.—Pac//ic  Medical  Journal,  Oct.  1892. 


Vaughan  &  Novy  on  Ptomaines  and  Leucomaines. 

New  (2d)  Edition. 
PTOMAINES,  LEUCOMAINES  AND  BACTERIAL  PRO- 
teids ;  or  the  Chemical  Factors  in  the  Causation  of  Disease.  By 
Victor  C.  Vaughan,  Ph.D.,  M.D.,  Professor  of  Physiological  and  Pathologi- 
cal Chemistry  and  Associate  Professor  of  Therapeutics  and  Materia  Medica  in 
the  University  of  Michigan,  and  Frederick  G.  Novy,  M.  D.  ,  Instructor  in 
Hygiene  and  Physiological  Chemistry  in  the  University  of  Michigan.  New 
(second)  edition.     In  one  handsome  12mo.  volume  of  398  pp.     Cloth,  |2.25. 

The  fact  that  a  second  edition  appears 
within  three  years  of  the  first  is  suflScient 
proof  that  it  has  been  received  by  the  profes- 
sion with  more  than  common  interest.  This 
may  largely  be  accounted  for  by  the  system 


atic  arrangement  and  the  practical  manner 
which  the  authors  successfully  adopted  for  it. 
This  book  is  one  of  the  greatest  importance, 
and  the  modern  physician  who  accepts  bac- 


terial pathology  cannot  have  a  complete 
knowledge  of  this  subject  unless  he  has  care- 
fully perused  it.  To  the  toxicologist  the  sub- 
ject is  alike  of  great  import,  as  well  as  to  the 
hygienist  and  sanitarian.  It  contains  in- 
formation which  is  not  easily  obtained  else- 
where, and  which  is  of  a  kind  that  no  medi- 
cal thinker  should  be  without.— T-^c  ^men- 
can  Jour,  of  the  Med.  Sciences^  April,  1892. 


Clowes'  Chemical  Analysis— Third  Edition. 

AN  ELEMENTARY  TREATISE  ON  PRACTICAL  CHEM- 
istry  and  Qualitative  Inorganic  Analysis.  Specially  adapted  for  use  in 
Laboratories  of  Schools  aud  Colleges  and  by  Beginners.  By  Fkank  Cix)WES, 
D.  Sc,  London,  Senior  Science-Master  at  the  High  School,  Newcastle-under- 
Lyme,  etc.  Third  American  from  the  fourth  and  revised  English  edition. 
In  one  12mo.  volume  of  387  pages,  with  55  illustratious.     Cloth,  $2.50. 

Ralfe's  Clinical  Chemistry. 

CLINICAL  CHEMISTRY.  By  Charles  H.  Ealfe,  M.D., 
F.  R.  C.  P.,  Assistant  Physician  at  the  London  Hospital.  In  one  pocket-size 
'12mo.  volume  of  314  pages,  with  16  illustrations.  Limp  cloth,  red  edges, 
$1.50.     See  Students^  Series  of  Manuals,  at  end. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia 


ChemistrxJ    #    PharmacvJ    #_jrherapeutics. 
Charles'  Physiological  and  Pathological  Chemistry. 

THE  ELEMENTS  OF  PHYSIOLOGICAL  AND  PATHO- 

logical  Chemistry.  A  Handbook  for  Medical  Students  and  Practitioners. 
Containing  a  general  Account  of  Nutrition,  Foods  and  Digestion,  and  the 
Chemistry  of  the  Tissues,  Organs,  Secretions  and  Excretions  of  the  Body  in 
Health  and  in  Disease.  Together  with  the  methods  for  preparing  or  sepa- 
rating their  chief  constituents,  as  also  for  their  examination  in  detail,  and 
an  outline  syllabus  of  a  practical  course  of  instruction  for  students.  By 
T.  Cranstoun  Charles,  M.  D.,  F.  C.  S.,  M.  S.,  formerly  Assistant  Professor 
and  Demonstrator  of  Chemistry  and  Chemical  Physics,  Queen's  College, 
Belfast.    Octavo,  463  pp. ,  38  woodcuts  and  1  colored  plate.    Cloth,  $3.50. 


Parrish's  Pharmacy— Fifth  Edition. 

A  TREATISE  ON  PHARMACY :  Designed  as  a  Text-book  for 
the  Student,  and  as  a  Guide  for  the  Physician  and  Pharmacist.  With  many 
Formulae  and  Prescriptions.  By  Edward  Parrish,  Late  Professor  of  the 
Theory  and  Practice  of  Pharmacy  in  the  Philadelphia  College  of  Pharmacy. 
Fifth  edition,  thoroughly  revised,  by  Thomas  S.  Wiegand,  Ph.  G.  Octavo 
volume  of  1093  pages,  with  256  illus.     Cloth,  |5.00;  leather,  $6.00. 

There  is  nothing  to  equal  Parrish's  Phar- 
macy in  this  or  any  other  language.—- Zowdow 
Pharmaceutical  Journal. 

This  treatise  on  Pharmacy  is  as  indispen- 
sable to  the  dispensing  or  manufacturing 
druggist  and  student  of  pharmacy  as  Dun- 
glison's  Medical  Dictionary  is  to  the  doctor 


and  the  student  of  medicine.  It  has  ceased 
being  a  luxury,  and  has  become  a  necessity. 
The  work  is  not  merely  a  text-book  for  phar- 
macy students  and  druggists,  but  is  a  valua- 
ble guide  and  compend  for  the  physician 
and  medical  student. — The  Physician  and 
Surgeon,  April,  1884. 


Griffith's  Universal  Formulary. 

A  UNIVERSAL  FORMULARY,  containing  the  Methods  of 
Preparing  and  Administering  Officinal  and  other  Medicines.  The  whole 
adapted  to  Physicians  and  Pharmaceutists.  By  Kobekt  Eglesfield 
Griffith,  M.  D.  Third  edition,  thoroughly  revised,  with  numerous  addi- 
tions, by  John  M.  Maisch,  Phar.  D.,  Professor  of  Materia  Medica  and 
Botany  in  the  Philadelphia  College  of  Pharmacy.  In  one  octavo  volume  of 
775  pages,  with  38  illustrations.     Cloth,  $4.50;  leather,  |5.50. 


£ruce's  Materia  Medica  and  Therapeutics— 5th  Ed. 

MATERIA  MEDICA  AND  THERAPEUTICS.  An  Intro- 
duction to  Kational  Treatment.  By  J.  Mitchell  Bruce,  M.  D. ,  F.  R.  C.  P., 
Physician  and  Lecturer  on  Materia  Medica  and  Therapeutics  at  Charing 
Cross  Hospital,  London.  Fourth  edition,  12mo.,  591  pages.  Cloth,  |1.50. 
See  Students'  Series  of  Manuals^  at  end. 

The  pharmacology   and   tberapeutics  of 
each  drug  are  given  with  great  fullness,  and 


the  indications  for  rational  employment  in 


the  practical  treatment  of  diseaf  e  are  pointed 
out. — Medical  Chronicle,  May,  1891. 


LEA  BROTHERS  &  CO  ,  706,  708  &  710  Sansom  Street,  Philadelphia, 


Therapeutics  #  /Vlateria  /Vledica, 
Hare's  Practical  Therapeutics— ^^^  ^^^^  ™ust  ready. 

A  TEXT-BOOK  OF  PRACTICAL  THERAPEUTICS ;  With 
Especial  Keference  to  the  Application  of  Kemedial  Measures  to  Disease  and 
their  Employment  upon  a  Kationul  Basis.  By  Hobart  Amoky  Haee, 
B.  Sc,  M.  D.,  Professor  of  Materia  Medicaand  Therapeutics  in  the  Jefierson 
Medical  College  of  Philadelphia.  With  special  chapters  by  Drs.  G.  E.  de 
ScHWEiNiTZ,  Edward  Martin,  J.  Howard  Keeves  and  Barton  C. 
Hirst.  New  (third)  and  revised  edition.  In  one  handsome  octavo  volume 
of  689  pages.     Cloth,  $3.75;  leather,  $4.75. 


We  find  here  directions  for  the  use  of  the 
drugs  of  the  most  recent  introduction,  and 
the  very  latest  results  obtained  in  the  treat- 
ment of  disease  by  these  newer  remedies. 
There  is  also  a  list  of  drugs  arranged  accord- 
ing to  their  physiological  action,  and  a  list 
of  definitions  of  the  terms  used  to  designate 
classes  of  drugs.  In  a  word,  this  book  is  a 
treatise  on  drugs  and  other  remedial  meas- 
ures, with  especial  reference  to  their  practi- 
cal uses ;  and  also  a  treatise  on  diseases,  with 


full  directions  for  the  most  approved  treat- 
ment. The  book  closes  with  a  table  of  doses 
and  an  index  of  diseases  and  remedies. 
There  are  some  books  that  the  student  and 
practitioner  alike  would  do  well  to  purchase ; 
there  are  others  they  must  have.  To  this 
latter  class  belong  the  text-books  on  practical 
therapeutics.  Certainly  none  can  be  found 
either  more  practical  or  more  complete  than 
this.— 7%e  hatmial  Medical  Jieview,  Febru- 
ary 2, 1893. 


Hare's  System  of  Practical  Therapeutics— 3  Vols. 

A  SYSTEM  OF  PRACTICAL  THERAPEUTICS.  By  Ameri- 
can and  Foreign  Authors.  Edited  by  Hobaet  Amoey  Haee,  M.  D.^ 
Professor  of  Therapeutics  and  Materia  Medica  in  the  Jefferson  Medical  Col- 
lege of  Philadelphia.  In  a  series  of  contributions  by  seventy-eight  emi- 
nent authorities.  In  three  large  octavo  volumes  containing  3544  pages, 
with  434  illustrations.  Price,  per  volume:  Cloth,  $5.00;  leather,  |6.00; 
half  Russia,  $7.00.  For  sale  by  subscription  only.  Address  the  Fublishers. 
Full  prospectus  free  to  any  address  on  application. 

Stille  &  Maisch's  National  Dispensatory— 5th  Edition. 

THE  NATIONAL  DISPENSATORY.  Containing  the  Natural 
History,  Chemistry,  Pharmacy,  Actions  and  Uses  of  Medicines.  By  Alfeed 
Stille,  M.  D.,  LL.  D.,  Professor  Emeritus  of  the  Theory  and  Practice  of 
Medicine  and  of  Clinical  Medicine  in  the  University  of  Pennsylvania., 
and  John  M.  Maisch,  Phar.  D.,  Professor  of  Materia  Medica  and  Botany 
in  the  Philadelphia  College  of  Pharmacy.  New  (5th)  and  revised  edition. 
In  one  magnificent  imperial  octavo  vol.  of  about  1750  pp.,  with  about  315  elab- 
orate engravings.     In  Frees,     A  notice  of  the  previous  edition  is  appended,  i 

since  its  first  appearance  in  1879.    The  en- 


The  most  comprehensive,  elaborate  and 
accurate  work  of  the  kind  ever  printed  in 
this  country.  It  is  no  wonder  that  it  has 
become  the  standard  authority  for  both  the 
medical  and  pharmaceutical  professions,  and 
that  four  editions  have  been  required  to- 
supply  the  constant  and  increasing  demand 


tire  field  has  been  gone  over  and  the  various 
articles  revised  in  accordance  with  the  latest 
developments  regarding  the  attributes  and 
therapeutical  action  of  drugs. — Kansas  City 
Medical  Index, 


The  Students'  Quiz  Series-M^'^-  «|?:  *slS  ^m^^'^^^^- 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Therapeutics  #  Materia  ^edica — (Cont^d), 
Brunton's  Therapeutics  and  Mat.  Med.— 3d  Edition. 

A  TEXT-BOOK  OF  PHARMACOLOGY,  THERAPEUTICS 

and  Materia  Medica  ;  Including  the  Pharmacy,  the  Physiological  Action 
and  the  Therapeutical  Uses  of  Drugs.  By  T.  Lauder  Brunton,  M.  D., 
D.  Sc,  F.  R.  S.,  F.  R.  C.  P.,  Lecturer  on  Materia  Medica  and  Therapeutics  at 
St.  Bartholomew's  Hospital,  London,  etc.  Adapted  to  the  U.  S.  Pharmaco- 
poeia by  Francis  H.  Williams,  M.  D.,  of  Harvard  Univ.  Med.  School. 
Third  edition.     Octavo,  1305  pages,  230  illus.     Cloth,  |5.50;  leather,  |6.50. 


No  words  of  praise  are  needed  for  this  work, 
for  it  has  already  spoken  for  itself  in  former 
editions.  It  was  by  unanimous  consent 
placed  among  the  foremost  books  on  the  sub- 
ject ever  published  in  any  language,  and 
the  better  it  is  known  and  studied  the  more 
highly  it  is  appreciated.  The  present  edition 
contains  much  new  matter,  the  insertion  of 
which  has  been  necessitated  by  the  advances 


made  in  various  directions  in  the  art  of 
therapeutics,  and  it  now  stands  unrivalled 
in  its  thoroughly  scientific  presentation  of 
the  modes  of  drug  action.  No  one  who 
wishes  to  be  fully  up  to  the  times  in  this 
science  can  aflTord  to  neglect  the  study  of  Dr. 
Brunton's  work.  The  indexes  are  excellent, 
and  add  not  a  little  to  the  practical  value  of 
the  hooli.— Medical  Record,  May  25,  1889 


Farquharson's  Therapeutics— Fourth  Edition. 

A    GUIDE     TO     THERAPEUTICS     AND     MATERIA 

Medica.  By  Robekt  Farquhakson,  M.  D.,  F.  R.  C.  P.,  LL.  D.,  Lecturer 
on  Materia  Medica  at  St.  Mary's  Hospital  Medical  School,  London.  Fourth 
American,  from  the  fourth  English  edition.  Enlarged  and  adapted  to  the 
U.  S.  Pharmacopoeia.  By  Frank  Woodbury,  M.  D.,  Professor  of  Materia 
Medica  and  Therapeutics  and  Clinical  Medicine  in  the  Medico-Chirurgical 
College  of  Philadelphia.     In  one  12mo.  Yolume  of  581  pages.    Cloth,  $2.50. 

and  therapeutical  actions  of  various  remedies 
are  shown  in  parallel  columns.  This  aids 
greatly  in  fixing  attention  and  facilitates 
study.  The  American  editor  has  enlarged 
the  work  so  as  to  include  all  the  remedies 
and  preparations  in  the  United  States  Phar- 
macopoeia. Altogether  the  book  is  a  most 
valuable  addition  to  the  list  of  treatises  on 
this  most  important  subject. — ITie  American 
Practitioner  and  News,  November  9, 1889. 


Farquharson's  Therapeutics  and  3fateria 
Medica  has  struck  a  happy  medium  between 
excessive  brevity  on  the  one  hand  and 
tedious  prolixity  on  the  other.  Itdeals  with 
the  entire  list  of  drugs  embraced  in  the 
British  PharmacopoBia  in  such  a  way  as 
to  give  in  a  satisfactory  form  the  established 
indications  of  each,  excluding  all  irrelevant 
matter.  An  especially  attractive  feature  is 
an  arrangement  by  which  the  physiological 


Edes'  Therapeutics  and  Materia  Medica. 

A  TEXT-BOOK  OF  THERAPEUTICS  AND  MATERIA 
Medica.  Intended  for  the  Use  of  Students  and  Practitioners.  By  Robert 
T.  Edes,  M.  D.,  Jackson  Professor  of  Clinical  Medicine  in  Harvard  Uni- 
versity, Medical  Department.  Octavo,  544  pages.   Cloth,  |3. 50;  leather,  |4. 50. 


The  present  work  seems  destined  to  take  a 
prominent  place  as  a  text-book  on  the  sub- 
jects of  which  it  treats.  It  possesses  all  the 
essentials  which  we  expect  in  a  book  of  its 
kind,  such  as  conciseness,  clearness,  a  judi- 
cious classification,  and  a  reasonable  degree 
of  dogmatism.  The  student  and  young 
practitioner  need  a  safe  guide  in  this  branch 
of  medicine,  such  they  can  find  in  the  pre- 
sent author.  All  the  newest  drugs  of  prom- 
ise are  treated  of.    The  clinical  index  at  the 


end  will  be  found  very  useful.  We  heartily 
commend  the  book  and  congratulate  the 
author  on  having  produced  so  good  a  one. — 
N.  Y.  Medical  Journal,  February  18, 1888. 

Dr.  Edes'  book  represents  better  than  any 
older  book  -the  practical  therapeutics  of  the 
present  day.  The  book  is  a  thoroughly  prac- 
tical one.  The  classification  of  remedies  has 
reference  to  their  therapeutic  action. — Phar' 
maceutical  Era^  January,  1888. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadeiphla. 


Practice  #  Oiagnosis* 


Flinfs  Practice  of  Medicine— Sixth  Edition. 

A  TREATISE  ON  THE  PRINCIPLES  AND  PRACTICE 

of  Medicine.  Designed  for  the  Use  of  Students  and  Practitioners  of  Medi- 
cine. By  Austin  Flint,  M.  D.,  LL.  D.,  Professor  of  the  Principles  and 
Practice  of  Medicine  and  of  Clinical  Medicine  in  Bellevne  Hospital  Medical 
College,  N.  Y.  Sixth  edition,  thoroughly  revised  and  rewritten  by  the 
Author,  assisted  by  William  H.  Welch,  M.  D.,  Professor  of  Pathology, 
Johns  Hopkins  University,  Baltimore,  and  Austin  Flint,  Jr.,  M.  i)., 
LL.  D.,  Professor  of  Physiology,  Bellevue  Hospital  Medical  College,  N.  Y. 
In  one  very  handsome  octavo  volume  of  1160  pages,  with  illustrations. 
Cloth,  15.50;  leather,  $6.50. 


No  text-book  on  the  principles  and  prac- 
tice of  medicine  has  ever  met  in  this  country 
with  such  general  approval  by  medical  stu- 
dents and  practitioners  as  the  work  of  Pro- 
fessor Flint.  In  all  the  medical  colleges  of 
the  United  States  it  is  the  favorite  work  upon 
Practice ;  and,  as  we  have  stated  before  in 
alluding  to  it,  there  is  no  other  medical  work 
that  can  be  so  gene-ally  found  in  the  libra- 


ries of  physicians.  In  every  state  and  terri- 
tory of  this  vast  country  the  book  that  will  be 
most  likely  to  be  found  in  the  office  of  a 
medical  man,  whether  in  city,  town,  village, 
or  at  some  cross-roads,  is  JFlint's  Practice. 
We  make  this  statement  to  a  considerable 
extent  from  personal  observation,  and  it  is 
the  testimony  also  of  others.— (7mci»na<» 
Medical  News,  October,  1886, 


Flint's  Auscultation  and  Percussion— Fifth  Edition. 

A  MANUAL  OF  AUSCULTATION  AND  PERCUSSION; 

Of  the  Physical  Diagnosis  of  Diseases  of  the  Lungs  and  Heart,  and  of 
Thoracic  Aneurism.  By  Austin  Flint,  M.  D.,  LL.  D.,  Professor  of  the 
Principles  and  Practice  of  Medicine  in  Bellevue  Hospital  Medical  College, 
N.  Y.  Fifth  edition.  Edited  by  James  C.  Wilson,  M.  D.,  Lecturer  on 
Physical  Diagnosis  in  the  Jefferson  Medical  College,  Philadelphia.  In  one 
handsome  royal  12mo.  vol.  of  274  pages,  v^ith  12  illustrations.  Cloth,  $1.75. 

ite  text-book  with  medical  students.  As 
stated  by  the  editor,  its  vahie  is  to  be  dis- 
covered in  the  clearness  and  appropriateness 
of  its  style,  the  accuracy  of  its  statements, 
its  scientific  method,  and  the  practical  treat- 
ment of  subjects  at  once  difficult  and  essen- 
tial to  the  student  of  medicine.— Cincmna^i 


The  work  has  met  with  the  favorable  en- 
dorsement of  the  profession,  a  fifth  edition 
being  needed  to  meet  the  demand  for  it.  Pro- 
fessor Flint's  Practice  of  Medicine  has  raet 
with  a  success  that  has  never  been  equalled 
by  any  other  work  of  the  kind  in  this  coun- 
try. The  one  before  us  on  Physical  Diagno- 
sis  seems    also  to   have   become  a  favor- 


Medical  News^  February,  1891. 


Hartshorne's  Essentials  of  Practice— 5th  Edition. 

ESSENTIALS  OF  THE  PRINCIPLES  AND  PRACTICE 

of  Medicine.  A  Handbook  for  Students  and  Practitioners.  By  Henry 
Hartshorne,  M.  D.,  LL.  D.,  Lately  Professor  of  Hygiene  in  the  tlniversity 
of  Pennsylvania.  Fifth  edition,  thoroughly  revised  and  rewritten.  In  one 
royal  12mo.  volume  of  669  pages,  with  144  illustrations.     Cloth,  $2.75. 


The  Students'  Quiz  Series-||fvys^B«l!^i.TiE''?T 

LEA  BROTHEftS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Practice  #  Electricit\?  #  Diagnosis* 
Bristowe's  Practice  of  Medicine— 7th  Edition. 

A  TREATISE  ON  THE  SCIENCE  AND  PRACTICE  OP 

Medicine.  By  John  Syer  Bristowe,  M.  D.,  LL.  D.,  F.  li.  S.,  Senior 
Physician  to  and  Lecturer  on  Medicine  at  St.  Thomas'  Hospital,  London. 
Seventh  edition.     In  one  8vo.  vol.  of  1325  pages.    Cloth,  $6. 50 ;  leather,  |7. 50. 

peared.     It  is  a  work  that  is  built  on  a  stable 


llie  remarkable  regularity  with  which 
new  editions  of  this  text-book  make  their 
appearance  v.  striking  testimony  to  its  ex- 
cellence and  value.  This,  too,  in  spite  of  the 
numerous  rivals  for  the  favor  of  the  student, 
which  have  been  put  forth  within  the  sixteen 
years   since  Bristowe'a  Medicine  first   ap- 


foundation,  systematic,  scientific,  and  prac- 
tical, containing  the  matured  experience  of 
a  physician  who  has  every  claim  to  be  con- 
sidered an  authority,  and  composed  in  a  style 
which  attracts  the  practitioner  as  much  as 
the  student.— TAe  Lancet,  July  12, 1890. 


Fotliergill's  Handbook  of  Treatment— 3d  Edition. 

THE  PRACTITIONER'S  HANDBOOK  OF  TREATMENT ; 

Or,  the  Principles  of  Therapeutics.  By  J.  Milner  Fotiiergill,  M.D., 
Edin.,  M.  R.  C.  p.,  Lond.,  Physician  to  the  City  of  London  Hospital  for 
Diseases  of  the  Chest.  Third  edition.  In  one  8vo.  volume  of  661  pages. 
Cloth,  $3.75;  leather,  $4.75. 


This  is  a  wonderful  book.  If  there  be 
such  a  thing  as  "medicine  made  easy,"  this 
is  the  work  to  accomplish  this  result.— Vir- 
ginia Medical  Monthly,  June,  1887. 

We  do  not  know  a  more  readable,  practical 
and  useful  work  on  the  treatment  of  disease 
than  the  one  we  have  now  before  \x^.— Pacific 
Medical  and  Surgical  Journal,  Oct.  1887. 

While  the  work  should  be  attentively 
studied  by  every  medical  student,  yet  it  is  no 
less  adapted  to  the  wants  of  the  experienced 
physician,  who  has  been  educated  in  his  pro- 


fession with  the  impression  from  the  begin- 
ning that  the  treatment  of  disease  is  entiiely 
empirical.  There  is  no  work  in  the  English 
language  in  regard  to  which  we  are  so  im- 
pressed that  physicians  should  both  read  and 
study  as  this  work. — Cincinnati  Medical 
News,  June,  1887. 

It  is  an  excellent  practical  work  on  thera- 
peutics, well  arranged  and  clearly  expressed, 
useful  to  the  student  and  young  practitioner, 
perhaps  even  to  the  o\6..— Dublin  Journal  of 
Medical  Science,  March,  1888. 


Bartholow's  Medical  Electricity— Third  Edition. 

MEDICAL  ELECTRICITY.  A  Practical  Treatise  on  the 
Applications  of  Electricity  to  Medicine  and  Surgery.  By  Roberts  Bar- 
THOLOW,  A.  M.,  M.  D,,  LL.  D.,  Professor  of  Materia  Medica  and  General 
Therapeutics  in  the  Jefferson  Medical  College  of  Philadelphia,  etc.  Third 
edition.  In  one  very  handsome  octavo  volume  of  308  pages,  with  110 
illustrations.    Cloth,  $2.50. 

The  fact  that  this  work  has  reached  its 
third  edition  in  six  years,  and  that  it  has 
been  kept  fully  abreast  with  the  increasing 
use  and  knowledge  of  electricity,  demon- 
strates its  claim  to  be  considered  a  practical 
treatise  of  tried  value  to  the  profession.  The 
matter  added  to  the  present  edition  embraces 


the  most  recent  advances  in  electrical  treat- 
ment. The  illustrations  are  abundant  and 
clear,  and  the  work  constitutes  a  full,  clear 
and  concise  manual  well  adapted  to  the 
needs  of  both  student  and  practitioner.— 
The  Medical  News,  May  14, 1887. 


Broadbent  on  the  Pulse. 

THE  PULSE.  By  AV.  H.  Broadbent,  M.  D.,  F.  R.  C.  P.,  Lect- 
urer on  Medicine  at  St.  Mary's  Hospital,  London.  In  one  12mo.  volume  of 
312  pages.     Cloth,  |1.75.    See  Series  of  Clinieal  Manuals,  at  end. 

LEA  BROTHERS  &  CO.,  706,  708  &  7fO^Sansom  Street  Philadelphia. 


Practice  of  /Vledicine  ^  Throat  and  Nose. 
Lyman's  Practice  of  Medicine. 

A  TEXT  BOOK  OF  THE  PRINCIPLES  AND  PRACTICE 

of  Medicine,  For  the  Use  of  Medical  Students  and  Practitioners.  By 
Henry  M.  Lyman,  M.  D.,  Professor  of  the  Principles  and  Practice  of 
Medicine  in  Rush  Medical  College,  Chicago.  In  one  very  handsome  royal 
octavo  volume  of  926  pages,  with  180  illus.     Cloth,  $4,75,  leather.  |5.75. 

This  is  an  excellent  treatise  on  the  prac- 
tice of  medicine,  written   by  one  who  is  not 


only  familiar  with  his  subject,  but  who  has 
also  learned  through  practical  experience  in 
teaching,  what  are  the  needs  of  the  student, 
and  how  to  present  the  facts  to  his  mind  in 
the  most  readily  assimilable  form.  The 
reader  is  not  confused  by  having  presented 
to  him  a  variety  of  different  methods  of  treat- 
ment, among  which  he  is  left  to  choose  the  one 
most  easy  of  execution,  but  the  author  de- 
scribes the  one  which  is  in  his  judgment  the 
best.  What  the  student  should  be  taught  is 
the  one  most  approved  method  of  treatment. 


We  have  spoken  of  the  work  as  one  for  the 
student,  and  this  because  the  author  occu- 
pies so  prominent  a  position  as  a  teacher; 
but  we  would  not  be  understood  that  it  is 
adapted  only  for  students.  There  is  many  a 
practitioner  to  whom  this  work  will  be  of 
great  use.  He  will  find  here  each  subject 
presented  in  its  latest  aspect.  The  practical 
and  busy  man  who  wants  to  ascertain  in  a 
short  time  all  the  necessary  facts  concerning 
the  pathology  or  treatment  of  any  disease, 
will  find  here  a  safe  and  convenient  guide. 
—Medical  Record^  October  22, 1892. 


Whitla's  Dictionary  of  Treatment. 

A  DICTIONARY  OF  TREATMENT  ;  OR  THERAPEUTIC 

Index,  including  Medical  and  Surgical  Therapeutics.  By  William 
Whitla,  M.  D.,  Professor  of  Materia  Medica  and  Therapeutics  in  the 
Queen's  College,  Belfast.  Kevised  and  adapted  to  the  United  States  Phar- 
macopoeia.    In  one  square,  octavo  volume  of  917  pages.     Cloth,  $4.00. 

examined.  The  book  abounds  with  useful, 
practical  hints  and  suggestions,  and  the 
younger  practitioner  will  find  in  it  exactly 
the  help  he  so  often  needs  in  treatment  The 
most  experienced  members  of  the  profession 
may  usefully  consult  its  pages  for  the  pur- 
pose of  learning  what  is  really  trustworthy 
in  the  later  therapeutic  developments.— T^e 
Glasgow  Medical  Journal^  April,  1892, 


The  several  diseased  conditions  are  ar- 
ranged in  alphabetical  order,  and  the 
methods— medical,  surgical,  dietetic  and  cli- 
matic—by which  they  may  be  met,  consid- 
ered. On  every  page  we  find  clear  and  de- 
tailed directions  for  treatment,  supported 
by  the  author's  personal  authority  and  ex- 
perience, whilst  the  recommendations  of 
other  competent  observers  are  also  critically 


Seiler  on  the  Throat  and  Nose-^^^lfs^^^R^E^kTy^^ 

A  HANDBOOK  OF  DIAGNOSIS  AND  TREATMENT  OF 

Diseases  of  the  Throat,  Nose  and  Naso-Pharynx.    By  Carl  Seiler, 
M.  D.,    Lecturer  on    Laryngoscopy    in  the  University  of  Pennsylvania. 
Fourth  edition.     In  one  handsome  royal  12mo,  volume  of  about  400  pages, 
with  107  illustrations  and  2  colored  plates.     Cloth,  |2.25. 
A  notice  of  the  previous  edition  is  appended. 
The  object  of  the  volume  is  to  serve  as  a 


guide  to  students  of  laryngology  in  acquir- 
ing the  skill  requisite  to  the  successful  diag- 
nosis and  treatment  of  diseases  of  the  larynx 
and  naso-pharynx.    The  author  has  omitted 


all  purely  theoretical  considerations,  and 
lias  discussed  only  points  of  practical  impor- 
tance as  concisely  as  possible.  The  work 
may  be  used  as  a  ready  book  of  reference.— 
The  Cincinnati  Medical  News.  Jan.  1889. 

EYE,  EAR.  THROAT  AND  NOSE, 
$1.    SEE  PAGEl 


The  Students'  Quiz  Series- 

LEA  BROTHERS  &  CO.,  706,708  &  710  Sansom  Street  Philadelphia. 


Oiagiiosis  ^  Urinary?  &  ^cnal  &  Treatment 
Mnsser's  Medical  Diagnosis.    In  Press. 

A  PRACTICAL  TREATISE  ON  MEDICAL  DIAGNOSIS. 

For  the  Use  of  Students  and  Practitioners.  By  John  H.  Musser,  M.  D., 
Assistant  Professor  of  Clinical  Medicine,  University  of  Pennsylvania,  Phila- 
delphia.    In  one  octavo  volume  of  about  650  pages. 

Teo  on  Food  in  Health  and  Disease. 

FOOD  IN  HEALTH  AND  DISEASE.  By  I.  Burney  Yeo, 
M.  D.,  F.  E.  C.  P.,  Professor  of  Clinical  Therapeutics  in  King's  College, 
London.  In  one  12mo.  volume  of  590  pages.  Cloth,  $2.00.  Series  of 
Clinical  Manuals. 


Dr.  Yeo  supplies  in  a  compact  form  nearly 
all  that  the  practitioner  requires  to  know 
on  the  subject  of  diet.  The  work  is  divided 
into  two  parts— food  in  health  and  food  in 
disease.  Dr.  Yeo  has  gathered  together 
from  all  quarters  an  immense  amount  of 
useful  information  within  a  comparatively- 


small  compass,  and  he  has  arranged  and 
digested  his  materials  with  skill  for  the  use 
of  the  practitioner.  We  have  seldom  seen 
a  book  which  more  thoroughly  realizes  the 
object  for  which  it  was  written  than  this 
little  work  of  Dr.  Yeo.— British  Medical 
Journal,  Feb.  8,  1890. 


Teo's  Medical  Treatment— Jnst  Ready. 

A  MANUAL  OF  MEDICAL  TREATMENT  OR  CLINICAL 

Therapeutics.  By  I.  Bueney  Yeo,  M.  D.,  F.  R.  C.  P.,  Professor  of  Clin- 
ical Therapeutics  in  King's  College,  London.  In  two  12mo.  volumes, 
containing  1275  pages,  with  illustrations.     Cloth,  |5.50. 

Roberts  on  Urinary  and  Renal  Diseases— 4th  Ed. 

A  PRACTICAL  TREATISE  ON  URINARY  AND  RENAL 

Diseases,  Including  Urinary  Deposits.  By  Sm  William  Roberts, 
M.  D.,  Lecturer  on  Medicine  in  the  Manchester  School  of  Medicine,  etc. 
Fourth  American  from  the  fourth  London  edition.  In  one  handsome  octavo 
volume  of  609  pages,  with  81  illustrations.     Cloth,  $3.50. 

is  also  either  the  text-book  or  the  reference- 
book  in  most  of  the  medical  colleges  of  the 
country  that  have  a  special  chair  for  renal 
and   urinary   diseases.  —  Virginia  Medical 


The  constant  aim  of  the  author  has  been 
to  make  the  book  a  valuable  guide  to  the 
clinical  student.  It  is  doubtless  the  most 
generally  accepted  standard  work.  We  do 
not  see  how  any  general  practitioner  of  med- 
icine can  afford  to  be  without  the  book.    It 


Monthly,  November,  1885. 


Tbe  Tear-Book  of  Treatment  for  1893. 

A  COMPREHENSIVE  AND  CRITICAL  REVIEW  FOR 

Practitioners  of  Medicine  and  Surgery.    In  one  12mo.  volume  of  500 
pages.   Cloth,  |1.50    For  special  commutations  with  periodicals  see  page  32. 


With  comparatively  little  labor,  the  busy 
practitioner  gets  the  gist  of  medical  litera- 
ture the  world  over.    Every  branch  of  medi- 


cine is  covered— new  remedies,  old  ones  with 
new  applications,  new  operations,  all  receiv- 
ing attention.— iJ/edica^  Record. 


THE  YEAR-BOOKS  OF  TREATMENT  for  1891  and  1892 ;  485 

pages,  each  $1.50.    The  Year-Books  for  1886  and  1887, 

320-341  pages,  each,  $1.25. 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Pathologx?  &  Histologx^  &  l^act^r\oloQ^. 
Gibbes'  Pathology  and  Histology. 

PRACTICAL  PATHOLOGY  AND  MORBID  HISTOLOGY. 

By  Heneage  Gibbes,  M.  D.,  Professor  of  Pathology  in  the  University  of 
Michigan,  Medical  Department.  In  one  very  handsome  octavo  volume  of 
314  pages,  with  60  illustrations,  mostly  photographic.     Cloth,  $2.75. 

are  particularly  accurate  and  impart  to  the 


The  important  subject  is  brought  fully  up 
with  the  most  recent  advances.  All  the  de- 
tails of  practical  work  in  this  department 
are  given  in  the  most  lucid  manner,  so  that 
as  a  guide  it  will  prove  exceedingly  valuable. 
The  value  of  the  work  is  greatly  enhanced 
by  the  numerous  illustrations  of  morbid 
tissues  displayed.    These  photo-engravings 


work  advantages  not  possessed  by  any  other 
method  of  illustration.  The  section  on  Prac- 
tical Bacteriology  contains  all  the  instruction 
necessary.  It  is  a  model  of  the  kind,  and 
deserves  the  fullest  patronage  of  the  medical- 
student  world,— Nashville  Journal  of  Medi- 
cine and  Surgery^  October,  1891. 


Abbott's  Bacteriology. 

THE  PRINCIPLES  OF  BACTERIOLOGY.  A  Practical 
Manual  for  Students  and  Physicians.  By  A.  C.  Abbott,  M.  D.,  First  Assis- 
tant, Laboratory  of  Hygiene,  University  of  Pennsylvania,  Philadelphia.  In 
one  12mo.  volume  of  259  pages,  with  32  illustrations.     Cloth,  $2.  CO. 


Now  that  practical  bacteriology  forms  a 
specific  portion  of  the  medical  student's 
labors,  there  will  be  a  growing  call  for  man- 
uals of  the  science.  In  the  book  before  us 
instruction  is  afforded  in  all  laboratory 
manipulations,    and    sterilization,    culture 


media,  inoculations,  and  staining,  are  all 
dealt  with  in  a  careful  and  specific  manner. 
No  college  of  medicine  will  be  known  for 
such  that  does  not  in  the  next  few  years 
provide  for  teaching  bacteriology  to  its  stu- 
dents,— The  FhyUcian  and  Surgeon^  Mar.  '92. 


Klein's  Histology— Fourth  Edition. 

ELEMENTS  OF  HISTOLOGY.    By  E.  Klein,  M.  D.,  F.  R.  S., 

Joint  Lecturer  on  General  Anatomy  and  Physiology  in  the  Medical  School  of 
St.  Bartholomew's  Hospital,  London.  Fourth  edition.  In  one  12mo. 
volume  of  376  pages,  with  194  illustrations.  Limp  cloth,  |1.75.  See  Stif.- 
dents'  Series  of  Manuals,  at  end. 

Crisp,  concise,  straightforward,  his  descrip- 
tions proceed  from  animal  protoplasm  and 
the  simple  cell,  to  the  histology  of  every 
organ  of  the  human  body.  The  author  gives 
just  that  information  which  the  intelligent 


student  of  anatomy  wants  and  is  justified  in 
expecting,  but  which  he  is  often  denied.  The 
illustrations  are  as  excellent  as  is  the  matter 
they  Sidoin.— The  3Iictoscope,  January,  1890. 


Green's  Pathology  and  Morbid  Anatomy— 7tli  Ed. 

PATHOLOGY  AND  MORBID  ANATOMY.    By  T.  Henry 
Green,   M.  D.,   Lecturer  on  Pathology  and  Morbid  Anatomy  at  Charing 
Cross  Hospital  Medical  School,  London.     Sixth  American  from  the  seventh 
revised  English  edition.     Octavo,  539  pages,  167  engravings.     Cloth,  $2.75. 
This  book  presents  the  subject  in  so  satis-    ^'  "^  '"""''  '"^  *^  '"^'^       «'+.-"  «* 

factory  a  manner  as  to  be  not  only  favorably 
received  by  the  medical  profession,  but  to 


be  at  once  placed  in  the  enviable  position  of 
a  text-book  in  all  medical  schools.— TAe 
Cincinnati  Lancet  Clinic,  Oct.  19,  1889. 


The  Students'  Quiz  Series-«^TA'cTlS^$t''§ 


SEE  P.  1. 


LEA  BROTHERS  &  CO ,  706,  708  &  710  Sansom  Street,  Philadelphia. 


PathoL  ^  Histol.  m  gacterioL— (Cont.) 
Senn's  Surgical  Bacteriology— Second  Edition. 

SURGICAL  BACTERIOLOGY.  By  Nicholas  Senn,  M.D., 
Ph.D.,  Professor  ol'  Surgery  in  Kiish  Medical  College,  Chicago.  New 
(secoud)  edition.  In  one  handsome  octavo  of  268  pages,  with  13  plates,  of 
which  10  are  colored,  and  9  engravings.     Cloth,  |2.00. 


The  book  is  valuable  to  the  student,  but  its 
chief  value  lies  in  the  fact  that  such  a  compil- 
ation makes  it  possible  for  the  busy  practi- 
tioner, whose  time  for  reading  is  limited  and 
whose  sources  of  information  are  often  few, 


to  become  conversant  with  the  most  modern 
and  advanced  ideas  in  surgical  patholotfy, 
which  have  "laid  the  foundation  for  the 
wonderful  achievements  of  modern  surgery." 
—Annals  of  Surgery,  March,  1892. 


Payne's  General  Pathology. 

A  MANUAL  OF  GENERAL  PATHOLOGY.  Designed  as  an 
Introduction  to  the  Practice  of  Medicine.  By  Joseph  F.  Payne,  M.  D., 
F.  R.  C.  P.,  Senior  Assistant  Physician  and  Lecturer  on  Pathological  Anat- 
omy, St.  Thomas'  Hospital,  London.  Octavo  of  524  pages,  with  152  illus- 
trations, and  a  colored  plate.     Cloth,  $3.50. 

The  work  has  our  heartiest  commendation. 
Whether  regarded  as  a  text-book  for  the 
student,  or  as  a  work  of  reference  for  the 
scientific  practitioner,  it  has  no  equal  in  our 


language  on  the  subject  of  which  it  treats. 
—The  American  Journal  of  the  Medical 
Sciences,  February,  1889. 


Coats'  Pathology. 

A  TREATISE  ON  PATHOLOGY.  By  Joseph  Coats,  M.  D., 
F.  F.  P.  S. ,  Pathologist  to  the  Glasgow  Western  Infirmary.  In  one  octavo 
volume  of  829  pages,  with  339  illus.     Cloth,  $5.50;  leather,  $6.50. 


The  author,  owing  to  his  large  experience 
as  a  practical  pathologist,  has  written  a  book 
which  is  as  instructive  as  it  is  complete, 
being  brought  up  to  the  latest  advances 
in  that  science.  The  plan  of  the  book  is 
one  that  will  meet  with  universal  ap- 
proval. We  commend  the  work  as  fill- 
ing the  wants  of  the  practitioner  and  the 


student.  The  illustrations  are  mostly  new 
and  are  well  executed.  A  novel  feature, 
and  one  at  the  same  lime  very  useful,  is  the 
arrangement  of  the  index,  whereby  the 
derivation  of  all  technical  terms  is  given, 
so  that  this  portion  of  the  work  is,  as  it 
were,  a  medical  lexicon  in  itself.— iVew; 
Orleans  Med.  and  Surg.  Journal,  Feb.  1884. 


Schafer's  Histology— Second  Edition. 

THE  ESSENTIALS  OF  HISTOLOGY.  By  Edward  A. 
ScHAFER,  F.  R.  S.,  Jodrell  Professor  of  Physiology  in  University  College, 
London.  New  (second)  edition.  In  one  octavo  volume  of  311  pages,  with 
325  illustrations.     Cloth,  |3.00. 


This  work  now  appears  in  its  third  edition, 
revised  and  enlarged.  It  has  been  used  for 
some  time  past  as  the  text-book  on  its  subject 
in  a  large  number  of  colleges,  and  is  so  well 
and  favorably  known  by  teachers  and  stu- 
dents of  histology  that  a  discussion  of  the 
book  seems  unnecessary.  The  matter  is 
systematically  arranged  into  forty-five  les- 
sons for  the  careful  study  of   the  minute 


anatomy  of  the  various  tissues  of  the  body. 
Unimportant  details  are  omitted,  the  matter 
is  clearly  and  concisely  presented,  and  the 
large  number  of  cuts  employed  to  illustrate 
the  text  recommend  this  book  to  all  inter- 
ested in  histology.  An  appendix  containing 
directions  for  the  preparation  of  sections  for 
microscopic  study  is  added.— t/wtvem/y  Med' 
teal  Magaziney  January,  1893. 


LEA  BROTHERS  &  CO.,  706,  70^  S^  710  Sansom  Street,  Philadelphia. 


Nerves  #  E\?e  #  Ear  m  Throat  #  Nose. 
Gray  on  Nervons  and  Mental  Diseases. 

A  PRACTICAL  TREATISE  ON  NERVOUS  AND  MEN- 
tal  Diseases.  By  Landon  Caktek  Gray,  M.  D.,  Professor  of  Diseases  of 
the  Mind  and  Nervous  System  in  the  New  York  Polyclinic.  In  one  8vo. 
volume  of  681  pages,  with  168  illus.     Cloth,  $4.50;  leather,  $5.50. 


The  symptomatology  and  etiology  are  very 
thorough  and  complete  without  being  in  the 
least  verbose.  The  treatment  of  each  disease 
is  considered  in  all  its  details,  and  the  useful- 
ness of  the  most  recent  remedies  demon- 
strated. The  treatise  on  mental  diseases 
is  by  no  means  the  least  important  feature 
of  the  work.  The  student  is  not  confused 
by  a  bewildering  and  interminable  classifi- 


cation; on  the  contrary,  Dr.  Gray  has  at- 
tempted to  simplify  this  subject,  with  a  suc- 
cess which,  it  is  hoped,  other  authors  will 
not  be  slow  to  recognize  and  imitate.  The 
glossary  at  the  ena  of  the  volume  will  mate- 
rially assist  those  who  are  not  conversant 
with  neurological  terms  to  a  thorough  com- 
prehension ol  the  text. — Journal  of  Nervoits 
and  Mental  Disease,  Dec,  1892. 


Norris  &  Oliver's  Ophthalmology— Jnst  Ready. 

A  TEXT-BOOK  OF  OPHTHALMOLOGY.  By  William  F. 
NoRKis,  M.  D.,  Professor  of  Ophthalmology  in  the  Medical  Department  of 
the  University  of  Pennsylvania,  and  Charles  A.  Oliver,  M.  D.,  Surgeon 
to  Wills'  Eye  Hospital,  Phila.  In  one  octavo  vol.  of  641  pp.,  with  357  beau- 
tiful engrav.  and  5  col.  plates,  test-types,  etc.  Cloth,  $5.00  ;  leather,  $6.00. 
It  is  safe  to  say  that  in  the  rich  literature  of  Ophthalmology,  no  volume 
will  be  found  which  will  give  so  clear  and  satisfactory  an  exposition  of  its 
subject  in  all  practical  bearings.  Its  exceptionally  profuse  and  handsome 
series  of  illustrations  will  aid  materially  in  constituting  it  a  most  satisfactory 
work  for  the  student,  practitioner  and  specialist. 

Nettleship  on  the  Eye— Fifth  Edition. 

DISEASES  OF  THE  EYE.  By  Edward  Nettleship, 
F.  R.  C.  S.,  Ophthalmic  Surgeon  at  St.  Thomas'  Hospital,  London.  Fourth 
American  from  the  fifth  English  edition,  thoroughly  revised.  In  one  12mo. 
volume  of  500  pages,  with  164  illus.,  selections  from  Snellen's  test-types 
and  formulae,  and  a  colored  plate  for  detecting  color-blindness.     Cloth  $2.00. 

color-blindness  tests  and  a  collection  of  for- 


Four  large  American  editions  testify  to  the 
fact  that  it  is  a  favorite  text-book  in  Ameri- 
can colleges  as  well  as  to  the  extent  of  its 
use  among  practitioners  in  general  and 
special  branches.  Its  popularity  as  a  refer- 
ence-book is  due  to  the  practical  nature  of 
its  text  and  to  the  inclusion  of  text-types, 


mulse.  It  is  safe  to  predict  that  with  the 
extended  scope  noted  in  its  title,  this  handy 
volume  will  become  more  than  ever  a  favorite 
with  all  classes  of  readers.— Pac?/ic  Medical 
Journal,  December,  1890. 


Bnrnett'on  the  Ear— Second  Edition. 

THE  EAR;  ITS  ANATOMY,  PHYSIOLOGY  AND  Dis- 
eases. A  Practical  Treatise  for  the  Use  of  Medical  Students  and  Practi- 
tioners. By  Charles  H.  Burnett,  A.  M.,  M.  D  ,  Professor  of  Otology  in 
the  Philadelphia  Polyclinic.  Second  edition.  In  one  handsome  octavo 
volume  of  580  pages,  with  107  illustrations.     Cloth,  |4.00j  leather,  |5.00. 

Students'  Quiz  Series— ^^^' ^^^'  IHV^g^V  '"'^^'  *'• 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Surgery-  #  Ophthal.  ^  NeuroL— (Cont.) 
Holmes'  Treatise  on  Surgery— Fifth  Edition. 

A  TREATISE  ON  SURGERY;  ITS  PRINCIPLES  AND 

Practice.     By  Timothy  Holmes,  M.  A.,  Surgeon  and  Lecturer  on  Surgery 
at  St.  George's  Hospital,  London.     From  the  fifth  English  edition,  edited 
by  T.  Pickering  Pick,  F.  R.  C.  S.     In  one  octavo  volume  of  997  pages, 
with  428  illustrations.     Cloth,  |6.00  ;  leather,  $7.00. 
The  work  is  one  of  the  bsst  text-books  for    standard  text-book  on  the  principles   and 


students  and  practitioners  who  have  not  the 
time  to  wade  through  the  exhaustive  systems 
and  encylopaedias  of  surgery. — Atlanta  Medi- 
cal and  SurgicalJournal,  August,  1889. 

This  work,  which  has  now  arrived  at  its 
fifth  edition,  still  maintains  its  position  as  a 


practice  of  surgery.  Mr.  Pick  has  performed 
his  part  of  the  work  with  rare  judgment  and 
skill.  The  book  contains  many  original 
illustrations  which  add  much  to  its  merits 
as  a  whole.— The  Medical  Record,  Nov.  2, 1889, 


Carter  &  Frost's  Ophthalmic  Surgery. 

OPHTHALMIC  SURGERY.  By  R.  Brudenell  Carter, 
F.  R.  C.  S.,  Lecturer  on  Ophthalmic  Surgery  at  St.  George's  Hospital,  Lon- 
don, and  W.  Adams  Frost,  F.  R.  C.  S.  ,  Joint  Lecturer  on  Ophthalmic 
Surgery  at  St.  George's  Hospital,  London.  In  one  12mo.  volume  of  559 
pages,  with  91  engravings,  color-blindness  test,  test-types  and  dots  and 
appendix  of  formulse.     Cloth,  $2.25.     See  Series  of  Clinical  Manuals,  sit  end. 


This  work  belongs  to  the  series  of  clinical 
manuals  for  practitioners  and  students  of 
medicine,  which  Messrs.  Lea  Brothers  &  Co. 
have  in  process  of  publication.  The  works 
eohiprising  this  series,  as  we  have  mentioned 
before,  are  made  in  size,  arrangement,  etc., 
exceedingly  convenient  for  the  use  of  stu- 


dents in  attendance  upon  lectures,  and  for 
reference  by  practitioners  of  medicine.  We 
know  of  no  work  upon  ophthalmic  diseases 
so  well  adapted  for  reference  by  physicians 
and  for  use  of  students  in  attendance  upon 
lect\Jires.—Cincin7iati  Med.  News,  Aprils  1888. 


Ross  on  Nervous  Diseases. 


A  HANDBOOK   ON    DISEASES    OF   THE   NERVOUS 

System.  By  James  Ross,  M.  D.,  F.  R.  C.  P.,  LL.D.,  Senior  Assistant 
Physician  to  the  Manchester  Royal  Infirmary.  In  one  octavo  volume  of 
725  pages,  with  184  illustrations.     Cloth,  |4.50  ;  leather,  $5.50. 

This  admirable  work  is  intended  for  stu- 
dents of  medicine  and  for  such  medical  men 


as  have  no  time  for  lengthy  treatises.  Dr. 
Ross  holds  such  a  high  scientific  position 
that  any  writings  which  bear  his  name  are 
naturally  expected  to  have  the  impress  of  a 


powerful  intellect.  In  every  part  this  hand- 
book merits  the  highest  praise,  and  will  no 
doubt  be  found  of  the  greatest  value  to  the 
student  as  well  as  to  the  prsictitioner.— Edin- 
burgh Med.  Journal,  JsiJi.  1887. 


Hamilton  on  Nervous  Diseases— Second  Edition. 

NERVOUS  DISEASES ;  Their  Description  and  Treatment.     By 
Allan  McLane  Hamilton,  M.  D.,  Attending  Physician  at  the  Hospital 
for  Epileptics  and  Paralytics,   Blackwell's  Island,  N.  Y.     Second  edition,  , 
thoroughly  revised  and  rewritten.     In  one  octavo  volume  of  598  pages,  ' 
with  72  illustrations.     Cloth,  $4.00. 

We  do  not  well  see  how  the  student  or  I  author  claims  for  it— "a  manual  for  students 
practitioner  can  afford  to  be  without  this  and  practitioners."—  Virginia  Med.  Monthly^ 
book.    It  is  in  the  highest  sense  what  the  |  May,  1882. 

UA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street  Philadelphia, 


Surg, — (Cont.)  #  /Vlinor  Surg.  &  ^atidaQinQ. 
Roberts'  Modern  Surgery. 

THE    PRINCIPLES    AND    PRACTICE    OP    MODERN 

Surgery.  For  the  Use  of  Students  and  Practitioners  of  Medicine  and  Sur- 
gery. By  John  B.  Roberts,  M.  D.,  Professor  of  Anatomy  and  Surgery  in 
the  Philadelphia  Polyclinic.  Professor  of  the  Principles  and  Practice  of 
Surgery  in  the  Woman's  Medical  College  of  Pennsylvania.  In  one  octavo 
volume  of  780  pages,  with  501  illustrations.     Cloth,  |4.50  ;  leather,  $5.50. 


It  has  been  the  effort  of  the  author  to  pre- 
paie  a  volume  that  will  be  in  every  respect 
a  thoroughly  good  surgical  text-book.  Being 
a  teacher  of  surgery  both  in  college  and 
hospital,  he  understands  just  what  sort  of  a 
text-book  a  student  needs  from  which,  with 
the  aid  of  lectures,  to  acquire  a  knowledge  of 
surgery ;  and  he  has  prepared  his  manual  in 
accordance  with  this  knowledge.  While  he 
has  drawn  upon  his  own  experience,  he  has 


consulted,  as  he  states,  the  latest  literature 
of  all  kinds  bearing  upon  his  specialty. 
Though  there  are  many  works  upon  surgery 
of  great  excellence  that  have  been  before 
the  profession  for  some  time,  yet  there  are 
none  of  a  more  practical  character  than  that 
of  Dr.  Roberts.  It  is  filled  with  illustrations 
that  will  aid  much  in  elucidating  the  text- 
ile Cincinnati  Medical  News,  October,  1890. 


Ashhnrst's  Surgery— Fifth  Edition. 

THE  PRINCIPLES  AND  PRACTICE  OF  SURGERY.    By 

John  Ashhurst,  Jr.,  M.  D.,  Barton  Professor  of  Surgery  and  Clinical  Sur- 
gery in  the  University  of  Pennsylvania.  Fifth  edition,  enlarged  and  thor- 
oughly revised.  In  one  large  and  handsome  octavo  volume  of  1144  pages, 
with  642  illustrations.  Cloth,  $6.00  ;  leather,  |7.00. 
A  complete  and  mast  excellent  work  on 


surgery.  It  is  only  necessary  to  examine  it 
to  see  at  once  its  excellence  and  real  merit 
either  as  text-book  for  the  student  or  a  guide 
for  the  general  practitioner.  It  fully  con- 
siders in  detail  every  surgical  injury  and 
disease  to  which  the  body  is  liable,  and  every 


advance  in  surgery  worth  noting  is  to  be 
found  in  its  proper  place.  It  is  unquestion- 
ably the  best  and  most  complete  single  vol- 
ume on  surgery  in  the  English  language, 
and  cannot  but  receive  that  continued  ap- 
preciation which  its  merits  justly  demand.— 
Southern  Practitioner,  February,  1890. 


Wharton's  Minor  Surgery  and  Bandaging. 

MINOR  SURGERY  AND  BANDAGING.  By  Henry  R. 
Wharton,  M.  D.,  Demonstrator  of  Surgery  and  Lecturer  on  Surgical  Dis- 
eases of  Children  in  the  University  of  Pennsylvania.  In  one  very  handsome 
12mo.  volume  of  498  pages,  with  403  engravings,  many  being  photo- 
graphic.    Cloth,  13.00. 


Dr.  Wharton  has  written  a  book  especially 
designed  for  students  and  younger  prac- 
titioners, superior  in  many  respects  to  others 
on  this  subject.  The  portions  of  it  devoted 
to  bandaging  and  fracture-dressing  are  par- 
ticularly good.  Full  and  accurate  verbal 
descriptions  of  the  mode  of  applying  all  the 
important  bandages,  and  of  the  best  modern 
methods  of  treating  and  dressing  fractures 
and  dislocations,  are  supplemented  and  ren- 
dered still  more  valuable  by  a  number  of 
excellent  illustrations,  most  of  them  new. 
These  have  been  photographed  from  life. 


and  they  combine  the  advantages  of  clear- 
ness of  outline  and  accuracy  in  portraying 
the  various  turns  of  the  bandages  they  repre- 
sent. Thus  the  methods  of  application  of 
the  various  dressings  are  rendered  mot  e  easy 
of  apprehension  than  by  verbal  description. 
The  part  of  the  work  devoted  to  a  descrip- 
tion of  the  different  substances  and  ma- 
terials used  in  antiseptic  dressings  and 
operations  and  the  mode  of  their  preparation 
seems  also  excellent,— Medical  News,  Novem- 
ber 28, 1891. 


LEA  BROTHERS  &  CO.,  706,  708  <S  710  Sansom  Street,  Philadelphia. 


Surger\?— (Cont.)  m  Fractures  &  Pislocations 
Treves'  Operative  Surgery.  '' 

A  MANUAL  OP  OPERATIVE  SURGERY.  By  Freder- 
ick Treves,  F.  R.  C.  S.,  Surgeon  and  Lecturer  on  Anatomy  at  the  Lon- 
don Hospital.  In  two  8vo.  volumes  containing  1550  pages,  with  422 
original  engravings.     Complete  work,  cloth,  $9.00  ;  leather,  |11.00. 


We  have  no  hesitation  in  declaring  it  the 
best  work  on  the  subject  in  the  English  lan- 
guage, and  indeed,  in  many  respects,  the  best 
in  any  language.  It  cannot  fail  to  be  of  the 
greatest  use  both  to  practical  surgeons  and 
to  those  general  practitioners  who,  owing  to 
their  isolation  or  to  other  circumstances,  are 
forced  to  do  much  of  their  own  operative 
woTle..— Annals  of  Surgery^  March,  1892. 


It  ia  by  far  the  most  exhaustive,  compre- 
hensive and  thorough  work  on  the  subject 
presented  to  the  profession.  It  is  a  model 
text-book,  and  should  be  in  the  hands  of 
every  surgeon  and  physician  who  is  called 
upon  to  perform  surgical  operations.  It  is 
decidedly  the  most  perfect  work  of  the  kind 
ever  published. — The  Nashville  Journal  of 
Medicine  and  Surgery f  March  1, 1892. 


Erichsen's  Science  and  Art  of  Surgery— 8th  Edition. 

THE  SCIENCE  AND  ART  OP  SURGERY;  Being  a 
Treatise  on  Surgical  Injuries,  Diseases  and  Operations.  By  John  E. 
Erichsen,  F.  R.  S.,  F.  R.  C.  S.,  Professor  of  Surgery  in  University  College, 
London,  etc.  From  the  eighth  and  enlarged  English  edition.  In  two  large 
8vo.  volumes  containing  2316  pages,  with  984  engravings  on  wood.  Cloth, 
$9.00 ;  leather,  $11.00. 


For  many  years  this  classic  work  has  been 
made  by  preference  of  teachers  the  principal 


text-book  on  surgery  for  medical  students, 

nsla ' 

continental  languages   it   may  be   said  to 


"While  through  translations  into  the  leading 


guide  the  surgical  teachings  of  the  civilized 
world,  No  excellence  of  the  former  edition 
has  been  dropped  and  no  discovery,  device 
or  improvement  which  has  marked  the 
progress  of  surgery  during  the  last  decade 


has  been  omitted.  The  illustrations  are 
many  and  executed  in  the  highest  style  of 
art— Louisville  3Iedical  News,  Feb.  14, 1885. 

We  have  always  regarded  the  "Science 
and  Art  of  Surgery  "  as  one  of  the  best  surg- 
ical text-books  in  the  English  language,  and 
this  eighth  edition  only  confirms  our  previous 
opinion.  We  take  pleasure  in  cordially 
commending  it  to  our  readers.— Jlfedtca/ 
News,  April  11, 1885. 


Hamilton  on  Fractures  and  Dislocations— 8th  Edition. 

A  PRACTICAL  TREATISE  ON  PRACTURES  AND  Dis- 
locations. By  Frank  H.  Hamilton,  M.  D.,  LL.  D.,  Surgeon  to  Belle- 
vue  Hospital,  New  York.  New  (eighth)  edition,  revised  and  edited  by 
Stephen  Smith,  A.  M.,  M.  D.,  Professor  of  Clinical  Surgery  in  the  Uni- 
versity of  the  City  of  New  York.  In  one  very  handsome  8vo.  volume  of 
832  pages,  with  507  illustrations.     Cloth,  |5.50  ;  leather,  $6.50. 

It  has  received  the  highest  endorsement 
that  a  work  upon  a  department  of  surgery  can 
possibly  receive.  It  is  used  as  a  text-book 
in  every  medical  college  of  this  country. 
Its  great  merits  anpear  most  conspicuously 


in  its  clear,  concise,  and  yet  comprehensive 
statement  of  principles,  which  renders  it  an 


admirable  text-book  for  teacher  and  pupil, 
and  in  its  wealth  of  clinical  materials,  which 
adapts  it  to  the  daily  necessities  of  the  prac- 
titioner. We  consider  that  the  work  before 
us  should  be  in  the  library  of  every  prac- 
titioner.—Oincwna^i  Medical  News,  Febru- 
ary, 1891. 


Students'  Quiz  Series— Surgery,  $1.75.    See  p.  t 

L£A  BROTHERS  &  CO.,  706,  708  i  710  Sanson)  Street.  Philadelphia. 


Surgery  #  Fractures  &  Oislocations — (Cont.) 
Stimson's  Operative  Surgery— Second  Edition. 

A  MANUAL  OF  OPERATIVE  SURGERY.  By  Lewis  A. 
Stimson,  B.  a.,  M.  D.,  Professor  of  Clinical  Surgery  in  the  Medical  Fac- 
ulty of  the  University  of  the  City  of  New  York.  Second  edition.  In  one 
royal  12mo.  volume  of  503  pages,  with  342  illustrations.     Cloth,  |2.50. 

believe  that  it  contains  much  that  is  worthy 
of  imitsiiUm.— British  Medical  Journal,  Jan- 
uary 22, 1887. 


There  is  always  room  for  a  good  book,  so 
that  while  many  works  on  operative  surg- 
ery must  be  considered  superfluous,  that  of 
Dr.  Stimson  has  held  its  own.  The  author 
knows  the  difficult  art  of  condensation. 
Thus  the  manual  serves  as  a  work  of  refer- 
ence, and  at  the  same  time  as  a  handy  guide. 
It  teaches  what  it  professes,  the  steps  of 
operations.  In  this  edition  Dr.  Stimson  has 
sought  to  indicate  the  changes  that  have 
been  effected  In  operative  methods  and  pro- 
cedures by  the  antiseptic  system,  and  has 
added  an  account  of  many  new  operations 
and  variations  in  the  steps  of  older  opera- 
tions. We  do  not  desire  to  extol  this  man- 
ual above  many  excellent  standard  British 
publications   of   the  same    class,   still   we 


It  is  a  pleasure  to  call  attention  to  such  an 
admirable  book  from  the  pen  of  an  Ameri- 
can surgeon.  It  is  full  of  good  common 
sense,  and  may  be  taken  as  a  guide  in  the 
subject  of  which  it  treats.  It  would  be  hard 
to  point  out  all  the  excellences  of  this  book, 
and  it  is  hot  easy  to  find  defects  in  it.  We 
can  heartily  recommend  this  book  to  stu- 
dents and  practitioners  of  surgery,  who  will 
find  in  it  an  amount  of  attention  given  to 
the  details  of  operative  methods  which  can- 
not be  expected,  and  which  certainly  cannot 
be  found  in  the  larger  works  on  general 
surgery.— .4 ??ier.  Jour,  of  Med.  Set.,  A^r.  1886. 


Stimson  on  Fractures  and  Dislocations. 

A  TREATISE  ON  FRACTURES  AND  DISLOCATIONS. 

By  Lewis  A.  Stimson,  M.  D.  In  two  octavo  volumes.  Vol.  L,  Frac- 
tures, 582  pages,  360  illus.  Vol.  II.,  Dislocations,  540  pages,  163  illus. 
Complete  work,  cloth,  $5.50  ;  leather,  $7.50.  Either  volume  separately, 
cloth,  $3.00;  leather,  $4.00. 


The  appearance  of  the  second  volume 
marks  the  completion  of  the  author's  origi- 
nal plan  of  preparing  a  work  which  should 
present  in  the  fullest  manner  all  that  is 
known  on  the  cognate  subjects  of  Fractures 
and  Dislocations.  The  volume  on  Frac- 
tures assumed  at  once  the  position  of  author- 
ity on  the  subject,  and  its  companion  on 
Dislocations  will  no  doubt  be  similarly  re- 
ceived.   The  closing  volume  of  Dr.  Stimson's 


work  exhibits  the  surgery  of  dislocations  as 
it  is  taught  and  practised  by  the  most  emi- 
nent surgeons  of  the  present  time.  Contain- 
ing the  results  of  such  extended  researches 
it  must  for  a  long  time  be  regarded  as  an 
authority  on  all  subjects  pertaining  to  dis- 
locations. Every  practitioner  of  surgery  will 
feel  it  incumbent  on  him  to  have  it  for  con- 
stant reference.— Cincm/»a/i  Medical  News, 
May,  1888. 


Gant's  Students'  Surgery. 


THE  STUDENT'S  SURGERY.  A  3fuUum  in  Parvo.  By 
Frederick  James  Gant,  F.  E.  C.  S.,  Senior  Surgeon  to  the  Royal  Free 
Hospital,  London.  In  one  square  octavo  volume  of  848  pages,  with  159 
engravings.     Cloth,  $3.75. 


The  author  of  this  work  for  students  has 
succeeded  admirably  in  his  endeavor  to  pre- 
sent to  the  beginner  his  material  in  such  a 
way  that  he  may  "  acquire  a  sound  matter- 
of-lact  knowledge  of  injuries  and  surgical 
diseases,  in  their  various  forms,  and  of  their 
diagnosis  and  treatment— including  surgical 
operations;  the  knowledge  of  which,  as 
divested  of  all  theory,  may  be  said  to  con- 


stitute positive  surgery."  The  work  is,  of 
course,  not  as  exhaustive  as  larger  and  more 
ambitious  ones,  but  will  prove  a  great  boon 
to  the  student  who  may  want  to  get  the 
kernel  without  much  husk.  The  author  is 
concise  and  pointed  in  his  style,  and  we 
heartily  recommend  the  work  to  the  student 
of  surgery.— JAe  Canada  Lancet,  April,  1890. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street  Philadelphia. 


Surgcr\?  #  General  and  Operative— (Cont.), 
Smith's  Operative  Surgery— Second  Edition. 

THE  PRINCIPLES   AND  PRACTICE  OF  OPERATIVE 

Surgery.  By  Stephen  Smith,  M*.  D.,  Professor  of  Clinical  Surgery  in 
the  University  of  the  City  of  New  York.  Second  and  thoroughly  revised 
edition.  In  one  very  handsome  volume  of  892  pages,  with  1005  illustra- 
tions.    Cloth,  $4.00  ;  leather,  $5.00. 

known  for  operative  work.  It  can  be  truly 
said  that  as  a  handbook  for  the  student,  a 
companion  for  the  surgeon,  and  even  as  a 
book  of  reference  for  the  physician  not  es- 
pecially engaged  in  the  practice  of  surgery, 
this  volume  will  long  hold  a  most  conspicu- 
ous place,  and  seldom  will  its  readers,  no 
matter  how  unusual  the  subject,  consult  its 
pages  in  vain.  Its  compact  form,  excellent 
print,  numerous  illustrations,  and  especially 
its  decidedly  practical  character,  all  combine 
to  commend  it. — Boston  Medical  and  Surgical 
Journal,  May  10, 1888. 


Professor  Smith's  Operative  Surgery  may 
be  termed  a  model  text-book  in  ever^r  re- 
spect. Everyone  unites  in  regarding  it  as 
decidedly  the  best  work  upon  operative  sur- 
gery extant.— Nashville  Journal  of  Medicine 
and  Surgery,  April,  1887. 

This  excellent  and  very  valuable  book  is 
one  of  the  most  satisfactory  works  on  mod- 
ern operative  surgery  yet  published.  The 
book  is  a  compendium  for  the  modern  sur- 
geon. The  present  edition  is  much  enlarged, 
and  the  text  has  been  thoroughly  revised, 
so  as  to  give  the  most  improved  methods  in 
aseptic  surgery,  and  the  latest  instruments 


Bryant's  Practice  of  Surgery— Fourth  Edition. 

THE  PRACTICE  OF  SURGERY.  By  Thomas  Bryant, 
F.  R.  C.  S.,  Surgeon  and  Lecturer  on  Surgery  at  Guy's  Hospital,  London. 
Fourth  American  from  the  fourth  and  revised  English  edition.  In  one 
imperial  octavo  of  1040  pages,  with  727  illus.    Cloth,  $6.50  ;  leather,  $7.50. 

for  the  medical  student.  The  work  is  emi- 
nently clear,  logical  and  practical.— CAtca^'O 
Med.  Jour,  and  Examiner,  April,  1886. 


The  fourth  edition  of  this  work  is  fully 
abreast  of  the  times.  The  author  handles 
his  subjects  with  that  degree  of  judgment 
and  skill  which  is  attained  by  years  of  patient 
toil  and  varied  experience.  The  present 
edition  is  a  thorough  revision  of  those  which 
preceded  it,  with  much  new  matter  added. 
His  diction  is  so  graceful  and  so  logical,  and 
his  explanations  are  so  lucid,  as  to  place  the 
work  among  the  highest  order  of  text-books 


That  it  is  the  very  best  work  upon  surgery 
for  the  use  of  medical  students  we  think 
there  can  be  no  doubt.  The  author  seems 
to  have  understood  just  what  a  student  needs 
and  has  prepared  the  work  accordingly. — 
Cincinnati  Medical  News,  January,  1885. 


Druitt's  Modern  Surgery— Twelfth  Edition. 

MANUAL  OF  MODERN  SURGERY.  By  Egbert  Druitt, 
M.R.C.S.  Twelfth  edition,  thoroughly  revised  by  Stanley  Boyd,  F.K.C.S. 
In  one  8vo.  vol.  of  965  pages,  with  373  illus.    Cloth,  $4.00  ;  leather,  $5.00. 

sustained  popularity,  or  have  more  fully 
come  up  to  the  ideal  of  a  vade  mecum  than 
Druitt's  Surgery.  No  less  than  50,000  copies 
have  been  sold  in  England  alone,  while  in 


Every  part  of  the  book  shows  signs  of 
careful  and  judicious  revision,  and  while 
the  well-known  characteristics  of  Druitt's 
book,  which  have  been  appreciated  by  many 
generations  of  students,  are  preserved,  all 


the  chapters  have  been  brought  well  up  to 
date.^  The  most  important  alteration  made 
in  this  edition  is  the  incorporation  of  a  good 
account  of  antiseptic  surgery  in  all  its 
branches.  It  is  in  every  way  a  trustworthy 
text-book.— 2%«  London  Lancet,  June  4, 1887. 
An  admirable  edition  of  an  old  favorite. 
Few  books  have  enjoyed  a  wider  or  longer 


this  country  the  book  has  had  extensive  col- 
legiate recomnoendation  and  Federal  patron- 
age. We  have  no  hesitation  in  saying  that 
the  book  is  abreast  of  the  times,  and  desirable 
for  students,  and  especially  for  those  prac- 
titioners who  wish  their  book  for  surgical 
reference  to  be  in  the  most  condensed  form. 
—Medical  News,  Nov.  5, 1887. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Surg er\?  #  Orthopcgdics. 
Treves'  Manual  of  Surgery.    Tliree  Volumes. 

A  MANUAL  OF  SURGERY.  In  Treatises  by  Various 
Authors.  Edited  by  Fredekick  Treves,  F.  R.  C.  S.,  Surgeon  and  Lect- 
urer on  Anatomy  at  the  London  Hospital.  In  three  12nio.  volumes  con- 
taining 1866  pages,  with  213  engravings.  Price  per  set,  cloth,  |6.00.  See 
Students'  Series  of  Manuals,  at  end. 


.  This  book  is  a  successful  attempt  to  repre- 
sent the  principles  and  practice  of  modern 
surgery,  in  the  form  and  manner  most  ac- 
ceptable to  the  greatest  number  of  practi- 
tioners and  medical  students.  AH  the  articles 
are  of  a  high  order  of  merit.  The  Manual  is 
destined  to  become  popular  both  as  a  text- 
book and  as  a  book  of  reference,  and  to  take 
rank  with  the  standard  works  on  surgery. — 
Chicago  Med.  Jour,  and  Examiner^  Dec.  1886. 
Mr.  Treves'  Manual  is  a  worthy  compeer 
of  the  excellent  manuals  and  handbooks  of 


surgery  wliich  have  been  given  to  us  by 
Erichsen,  Holmes,  and  Bryant.  The  names 
of  the  authors  of  the  several  treatises  are  a 
guarantee  for  the  quality  of  the  work. 
Each  author  has  set  himself  to  write  a  good, 
plain,  lucid  article  on  the  subject  assigned  to 
him,  and  all  appear  to  have  succeeded. 
What  is  professed  is  well  done,  and  the  re- 
sult is  a  book  which  students  may  well  learn 
from  and  practitioners  may  well  refer  to. — 
The  Practitioner ^  June,  188G. 


Treves'  Handbook  of  Surgical  Operations. 

THE  STUDENT'S  HANDBOOK  OF  SURGICAL  OPER- 

ations.     By  the  same  Author.     In  one  square  12mo.  volume  of  508  pages, 
with  94  illustrations.     Cloth,  |2.50.     Just  ready. 


The  present  work  is  intended  for  the  use 
of  students  who  are  preparing  for  the  final 
examinations,  or  who  need  a  handbook  to 
assist  them  in  carrying  out  operations  upon 
the  dead  body.  It  concerns  itself  only  wiih 
the  most  essential  and  most  commonly  per- 
formed operations.  The  volume  contains  the 
very  latest  teachings,  so  far  as  they  concern 


the  technique  of  operative  work.  The  opera- 
tions are  characterized  throughout  by  surgi- 
cal judgment,  anatomical  accuracy,  and 
practical  familiarity  with  the  subjects  under 
condderation.  The  illustrations  are  good 
and  the  size  is  convenient.— ilfedicff/  News^ 
Oct.  1, 1892. 


Gould's  Surgical  Diagnosis. 

ELEMENTS  OF  SURGICAL  DIAGNOSIS.  By  A.  Psarce 
Gould,  F.  R.  C.  S.,  Assistant  Surgeon  to  Middlesex  Hospital.  In  one  12mo. 
volume  of  589  pages.     Cloth,  $2. 00.     See  Students^  Series  of  3Ianuals,  at  end. 


The  simple,  unpretending  volume  is,  like 
its  author,  accurate  and  scholarly.  No  im- 
portant facts  with  reference  to  surgical 
diagnosis  have  been  omitted.  To  charac- 
terize Mr.  Gould's  system  in  a  few  words,  we 
should  say  that  it  was  eminently  analytical 
and  practical.  He  believes  in  using  common 
sense  above  all  in  making  a  diagnosis,  and, 
moreover,  in  following  a  method.    In  our 


opinion  his  book  will  prove  an  invaluable 
aid  to  students,  and  it  will  be  an  excellent 
idea  for  practitioners  to  acquire  the  habits 
of  care  and  accuracy  which  it  inculcates. 
But  the  best  thing  about  Mr.  Gould's  book  is 
that  it  is  not  a  compilation;  it  is  the  out- 
growth of  experience,  and  is  correspondingly 
valuable.— iVew;  York  M-  d.  Jour.,  May  30, 1885. 


Young's  Orthopadic  Surgery.    Preparing. 

A  MANUAL  OF  ORTHOPEDIC  SURGERY,  FOR  STU- 
dents  and  Practitioners.  By  James  K.  Young,  M.  D.,  Instructor  in 
Orthopaedic  Surgery,  University  of  Pennsylvania,  Philadelphia.  In  one 
12mo.  volume  of  about  400  pages,  fully  illustrated. 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Sl<in  #  Genito^Urinarx?  and  Venereal. 
Jackson  on  tbe  Skin 

THE  READY-REFERENCE  HANDBOOK  OF  DISEASES 

of  the  Skin.  By  Geoege  Thomas  Jackson,  M.  D.,  Professor  of  Der- 
matology, Women's  Medical  College,  New  York  Infirmary.  In  one  12mo. 
volume  of  534  pages,  with  50  illustrations  and  a  colored  plate.   Cloth,  $2.75. 

and  external  use  is  of  no  little  value. — The 


The  author's  large  experience  as  a  practi- 
tioner and  teacher  has  been  brought  to  bear 
in  producing  a  work  admirably  adapted  to 
convey  a  practical  knowledge  of  dermatol- 
ogy. It  would  be  difl&cult  to  conceive  of  a 
work  more  exactly  suited  to  the  needs  of 
both  students  and  practitioners.  Richly 
illustrated,  issued  in  convenient  form,  and 
at  a  price  within  the  means  of  all,  the 
volume  is  assured  of  wide  usefulness.  The 
alphabetical  arrangement  of  the  diflerent 
diseases  has  been  adopted,  making  it  exceed- 
ingly convenient  for  ready  reference.  An 
appendix  of  quite  a  number  of  formulae  for 
baths,  combinations  of  drugs  for  internal 


Southern  Practitioner^  January,  1893. 

This  is  a  plain,  practical  survey  of  skin 
diseases,  intended  to  present  dermatology 
as  it  now  exists.  Symptomatology,  diagnosis 
and  treatment  occupy  the  first  place.  To  the 
general  practitioner  and  the  student  of  der- 
matology it  is  especially  useful.  Well-tried 
and  valuable  formulae  are  given,  and  there  is 
a  good  index.  Clearness,  common  sense  and 
simplicity  are  the  qualiiies  that  chiefly  com- 
mend this  admirable  handbook  to  the  stu- 
dent.— The  New  York  Medical  Journal.  Novem- 
ber 19, 1892. 


Hardaway's  Manual  of  Skin  Diseases. 

MANUAL  OF  SKIN  DISEASES.  With  Special  Reference 
to  Diagnosis  and  Treatment.  For  the  Use  of  Students  and  General  Practi- 
tioners. By  W.  A.  Hardaway,  M.  D.,  Prof  of  Skin  Diseases  in  the  Mis- 
souri Med.  Col.,  St.  Louis.     In  one  12mo.  vol.  of  440  pages.     Cloth,  $3.00. 

diagnoses  clearly  given,  while  the  sections 


This  Manual  is  conveniently  arranged  to 
serve  students  and  practitioners  as  a  practi- 
cal guide  in  the  study  of  skin  diseases.  The 
subjects  are  arranged  alphabetically  for 
quick  reference.  The  descriptions  of  the 
diseases  are  well  made,  and  their  causes  and 


on  treatment  of  each  of  the  diseases  are 
based  mostly  on  practical  experience  of 
many  years  of  the  author  as  a  distinguished 
specialist.— Fa.  Med.  Monthly^  Sept.  1892. 


Culver  &  Hayden  on  Venereal  Diseases. 

A   MANUAL   OF    VENEREAL    DISEASES.     By  E.  M. 

Culver,  M.  D.,  Pathologist  and  Assistant  Attending  Surgeon,  Manhattan 
Hospital,  N.  Y.,  and  J.  R.  Hayden,  M.D.,  Chief  of  Clinic  Venereal  De- 
partment, Yanderbilt  Clinic,  College  of  Physicians  and  Surgeons,  N.  Y. 
In  one  12mo.  volume  of  289  pages,  with  33  illustrations.     Cloth,  $1.75. 

In  this  little  volume  the  authors  have  have  had  a  wide  range  of  experience,  and 
succeeded  admirably  in  giving  the  student  that  they  have  cultivated  their  opportunities 
and  practitioner  an  epitome  of  our  knowl-  a  perusal  of  their  work  will  testify.  The 
edge  of  the  venereal  diseases.  The  book  book  is  one  of  the  best  manuals  of  its  kind 
contains  nothing  foreign  to  the  subjects  to  for  the  busy  physician  and  for  the  student, 
be  treated,  and  abounds  in  hints  and  sug-  —New  York  MedicalJournalf  J  a.n.2Sf  1892. 
gestions  of  practical  value.     The  authors 


The  Students'  Quiz  Series. 

OESITO-UBINABY  AND  VENEREAL  DISEASES,  $1.;  SKIN  DISEASES,  $1. 

SEE  PAOE  1. 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphfa.        ' 


Venereal  and  S[<in  Diseases— (Continued) 
Taylor  on  Venereal  Diseases— New  Ed.    Preparing. 

THE  PATHOLOGY  AND  TREATMENT  OF  VENEREAL 

Diseases.  Including  the  results  of  recent  investigations  upon  the  subject. 
By  R.  W.  Taylor,  A.  M.,  M.  D.,  Clinical  Professor  of  Genito-Urinary  Dis- 
eases in  the  College  of  Physicians  and  Surgeons,  New  York,  Professor  of 
Venereal  and  Skin  Diseases  in  the  University  of  Vermont.  Being  the 
sixth  edition  of  Bumstead  and  Taylor,  entirely  rev^ritten  by  Dr.  Taylor. 
Large  8vo.  volume  about  900  pages,  with  about  150  engravings,  as  well  as 
numerous  chromo-lithographs.  In  active  preparation. 
A  notice  of  the  previous  edition  is  appended. 


The  character  of  this  standard  work  is  so 
well  known  that  it  would  be  superfluous 
here  to  pass  in  review  its  general  or 
special  points  of  excellence.  The  verdict  of 
the  profession  has  been  passed;  it  has  been 
accepted  as  the  most  thorough  and  complete 
exposition  of  the  pathology  and  treatment 


of  venereal  diseases  in  the  language;  admir- 
able as  a  model  of  clear  description,  an  ex- 
ponent of  sound  pathological  doctrine,  and 
a  guide  for  rational  and  successful  treat- 
ment, it  is  an  ornament  to  the  medical  liter- 
ature of  this  couniry.— Journal  oj  Cutaneous 
and  Venereal  Diseases. 


Hyde  on  the  Skin— Second  Edition. 


A    PRACTICAL    TREATISE  ON  DISEASES  OF  THE 

Skin.  For  the  Use  of  Students  and  Practitioners.  By  James  Nevins 
Hyde,  A.  M.,  M.  D.,  Professor  of  Dermatology  and  Venereal  Diseases  in 
Rush  Medical  College,  Chicago.  Second  edition.  In  one  octavo  volume  of 
676  pages,  with  2  colored  plates  and  85  illus.     Cloth,  $4.50  ;  leather,  $5.50. 

valuable  and  creditable  addition  to  Ameri- 


In  this  volume  the  author  has  supplied  the 
student  with  a  work  of  standard  value. 
While  thorough  and  comprehensive  in  the 
description  of  disease,  it  is  especially  helpful 
in  the  matter  of  treatment.  In  this  regard 
it  leaves  nothing  to  the  presumed  knowledge 
of  the  reader,  but  enters  thoroughly  into  the 
most  minute  descriptions,  so  that  one  is  not 
only  told  what  should  be  done  under  given 
conditions,  but  how  to  do  it  as  well.  Care 
has  been  taken  also  to  render  the  nomen- 
clature as  clear  and  unconfusing  as  the  pres- 
ent state  of  dermatology  will  admit.  The 
book  la  one  we  can  heartily  recommend  as  a 


can  dermatological  literature  and  a  reliable 
guide  for  students  and  practitioners.— :/7ie 
Amer.  Practitioner  and  ^ews,  Sept.  29,  1888. 

We  can  heartily  recommend  it,  not  only  as 
an  admirable  text-book  for  teacher  and 
student,  but  in  its  clear  and  comprehensive 
rules  for  diagnosis,  its  sound  and  independ- 
ent doctrines  in  pathology,  and  its  minute 
and  judicious  directions  for  the  treatment  of 
disease,  as  a  most  satisfactory  and  complete 
practical  guide  for  the  physician.— 2%e 
Amer.  Jour,  of  the  Med.  Sciences,  July,  1888. 


Fox's  Epitome  of  Skin  Diseases— Third  Edition. 

AN  EPITOME  OF  SKIN  DISEASES.  With  Formulae. 
For  Students  and  Practitioners.  By  Tilbuky  Fox,  M.  D.,  Physician  to  the 
Dep.  for  Skin  Diseases,  Univ.  College  Hospital,  London,  and  T.  Colcott 
Fox,  M.  R.  C.  S.,  Physician  for  Diseases  of  the  Skin  to  the  Westminster 
Hosp.,  London.     Third  edition,  12mo.,  238  pages.     Cloth,  $1.25. 

The  little  handbook  will  prove  alike  valu-  |  which  reference  is  made  in  preceding  pages, 
able  to  the  student  and  practitioner  of  medi-    The  work  is  most  excellently  arranged  and 
cine,  being  as  it  is,  an  epitome,  yet  quite    will,  we  are  satisfied,  be  highly  appreciated, 
full  and  complete.    The  pharmacopoeia  em-    —The  Southern  Practitioner,  February,  1884. 
braces  a  series  of  very  valuable  formulae  to  I 

LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia, 


Thomas  &  Munde  on  Diseases  of  Women— 6th  Ed. 

A   PRACTICAL  TREATISE  ON   THE   DISEASES    OP 

Women.  ByT.  Gaillard  Thomas,  M.  D.,  LL.  D.,  Emeritus  Professor 
of  Diseases  of  Women  in  the  College  of  Physicians  and  Surgeons,  New 
York,  and  Paul  F.  Munde,  M.  D.,  Professor  of  Gynecology  in  the  New 
York  Polyclinic.  New  (sixth)  edition,  thoroughly  revised  and  rewritten 
by  Dr.  Munde.  In  one  large  and  handsome  octavo  volume  of  624  pages, 
with  347  illustrations,  of  which  201  are  new.  Cloth,  $5.00;  leather,  $6.00. 
The  profession  has  sadly  felt  the  want  of  I  a  -writer  as  Dr.  Munde,  was  hailed  with  de- 
a  text-book  on  diseases  of  women,  which  light.  The  result  is  what  is  perhaps,  on  the 
should  be  comprehensive,  and  at  the  same  whole,  the  best  practical  treatise  on  the  sub- 
time  notdiflfuse,  systematically  arranged  so  I  ject  in  the  Eoglish  language.  Itis,  aswehave 
as  to  be  easily  grasped  by  the  student  of    said,  the  best  text-book  we  know,  and  wi" 


limited  experience,  and  which  should  em- 
brace the  wonderful  advances  which  have 
been  made  within  the  last  two  decades. 
Thomas'  work  fulfilled  these  conditions,  and 
the  announcement  that  a  new  edition  was 
about  to  be  issued,  revised  by  so  competent 


be  of  special  value  to  the  general  practitioner 
as  well  as  to  the  specialist.  The  illustra- 
tions are  very  satisfactory.  Many  of  them 
are  new,  and  are  particularly  clear  and  at- 
trSiCtiye.— Boston  Medical  and  Surgical  Jour» 
nal,  January  14, 1892. 


Davenport's  Non-Surgical  Gynaecology— 2d  Edition. 

DISEASES  OF  WOMEN;   A  MANUAL  OF  NON-SUR- 

gical  Gynaecology.  Designed  especially  for  the  Use  of  Students  and 
General  Practitioners.  By  F.  H.  Davenpokt,  M.  D.,  Assistant  in  Gynae- 
cology in  the  Medical  Dept.  of  Harvard  University,  Boston.  Nevsr  (second) 
edition.    In  one  12mo.  volume  of  314  pages,  with  107  illus.    Cloth,  $1.75. 

in  the  future  intends  to  make  gynaecology 
his  life-work,  we  believe  that  Davenport's 


It  teaches  the  physician  or  the  student  how 
4o  do  the  little  things,  or  to  remedy  the 
minor  evils  in  connection  with  gynaecology. 
To  those  in  the  profession  who  are  about  to 
interest  themselves  particularly  in  this 
branch  of  surgery,  and  to  the  student  who 


book  will  be  essential  to  his  success,  because 
it  will  teach  him  facts  which  larger  works 
sometimes  ignore.— TAe  Therapeutic  Gazette, 
October  15, 1892. 


May's  Mannal  of  Diseases  of  Women— 2d  Edition. 

A  MANUAL  OF  THE  DISEASES  OF  WOMEN.  Being  a 
Concise  and  Systematic  Exposition  of  the  Theory  and  Practice  of  Gyne- 
cology. By  Charles  H.  May,  M.  D.,  Late  House  Surg,  to  Mt.  Sinai  Hosp., 
N.  Y.  Second  edition,  by  L.  S.  Rau,  M.  D.,  Attend.  Gynecologist  at  Harlem 
Hosp.,  N.  Y.    In  one  12mo.  of  360  pages,  with  31  illus.     Cloth,  $1.75. 

This  is  a  manual  of  gynecology  in  a  very    titioner  who  wishes  to  refresh  his  memory 
condensed  form,  and  the  fact  that  a  second  •-    •      -  ..... 

edition  has  been  called  for  indicates  that  it 
has  met  with  a  favorable  reception.  It  is 
intended,  the  author  tells  us,  to  aid  the  stu- 
dent who  after  having  carefully  perused  lar- 
ger works  desires  to  review  the  subject,  and 
he  adds  that  it  may  be  useful  to  the  prac- 


rapidly  but  has  not  the  time  to  consult  larger 
works.  We  are  much  struck  with  the  readi- 
ness and  convenience  with  which  one  can 
refer  to  any  subject  contained  in  this  vol- 
ume. Carefully  compiled  indexes  and  am- 
ple illustrations  also  enrich  the  work. — The 
Physician  and  Surgeon^  June,  1890. 


The  Students'  Quiz  Series— Gynecology,  $1.  See  P.  1. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


G\^n^COlog\? — (Continued) 

Emmet's  Gynaecology— Third  Edition. 

THE  PRINCIPLES  AND  PRACTICE  OF  GYNAECOLOGY; 

For  the  Use  of  Students  and  Practitioners  of  Medicine.  By  Thomas  Addis 
Emmet,  M.  D.,  LL.  D.,  Surgeon  to  the  Woman's  Hospital,  New  York,  etc. 
Third  edition,  thoroughly  revised.  In  one  large  and  very  handsome  octavo 
volume  of  880  pages,  with  150  illustrations.     Cloth,  |5.00;  leather,  |6.00. 

The  originality  and  amplitude  of  resource 
which  characterize  the  operative  procedures 
of  the  author  are  faithfully  mirrored  in  the 
goodly  volume  before  us.  Dr.  Emmet  simpli- 
fies the  treatment  of  diseases  of  women  ma- 


terially. The  original  and  practical  con- 
tributions form  a  pedestal  upon  which  his 
fame  must  securely  rest.  The  work  is  an  in- 
exhaustible fountain  of  elinicp^  information, 
which  no  practitioner  who  has  the  interest 
of  his  clientele  at  heart  can  afford  to  miss 


from  his  library.  Its  practical  teachings 
renderit  indispensable  to  the  general  prac- 
titioner, while  its  novel  views  and  opera- 
tions commend  it  to  the  progressive  gyne- 
cologist.—ilferftca/  Record,  December  20, 1884. 
Medical  students  and  physicians  will  find 
no  work  that  better  elucidates  the  etiology, 
pathology  and  treatment  of  diseases  of 
women.  It  is  a  treasury  of  valuable  practi- 
cal knowledge  set  forth  in  a  clear,  interest- 
ing style.— Cincinnati  Med.  News,  Jan.  1885. 


Edis  on  Women. 

THE  DISEASES  OF  WOMEN.  Including  their  Pathology, 
Causation,  Symptoms,  Diagnosis  and  Treatment.  A  Manual  for  Students 
and  Practitioners.  By  Akthur  W.  Edis,  M.  D.,  London,  F.  R.  C.  P., 
M.  R.  C.  S.,  Assistant  Obstetric  Physician  to  Middlesex  Hospital,  late  Phy- 
sician to  British  Lying-in  Hospital.  In  one  handsome  octavo  volume  of  576 
pages,  with  148  illustrations.    Cloth,  $3.00;  leather,  $4.00. 

the  more  common  methods  of  treatment, 
and  yet  very  little  is  said  about  them  in 
many  of  the  text-books.    The  book  is  one 


The  special  qualities  which  are  conspicu- 
ous are  thoroughness  in  covering  the  whole 
ground,  clearness  of  description  and  con- 
ciseness of  statement.  Another  marked 
feature  of  the  book  is  the  attention  paid  to 
the  details  of  many  minor  surgical  opera- 
tions and  procedures,  as,  for  instance,  the 
use  of  tents,  application   of  leeches,  and  use 


to  be  warmly  recommended  especially  to 
students  and  general  practitioners,  who  need 
a  concise  but  complete  r^sum^  of  the  whole 
subject.  Specialists,  too,  will  find  many 
useful  hints  in  its  p&gps.— Boston  Medical 


of  hot-water  injections.    These  are  among    and  Surgical  Journal,  March  2, 1882. 


Sutton  on  the  Ovaries  and  Fallopian  Tubes. 

SURGICAL  DISEASES  OF  THE  OVARIES  AND  FAL- 
lopian  Tubes,  including  Tubal  Pregnancy.  By  J.  Bland  Sutton, 
F.  R.C.  S.,  Assistant  Surgeon  to  the  Middlesex  Hospital,  London.  In 
one  crown  octavo  volume  of  544  pages,  with  119  engravings  and  5  colored 
plates.     Cloth,  $3.00. 


If  ever  the  writer  of  book  reviews  is  to  be 
pardoned  for  indulging  in  extravagant 
praise  of  a  new  work,  it  is  in  the  review  of 
the  Surgical  Diseases  of  the  Ovaries  and 
Fallopian  Tubes.  The  author  is  recognized 
the  world  over  as  an  authority  on  gyne- 
cological surgery,  and  his  many  contribu- 
tions to  medical  literature  have  at  once 
taken  rank  with  the  highest  class  of  medi- 
cal works.    The  book  before  us,  exhaustive 


of  the  subjects  treated,  breathes  a  spirit  of 
conservatism  which  can  but  be  beneficial  to 
operators  who  look  to  the  knife  as  the  only 
rational  treatment  for  almost  all  abdominal 
diseases.  The  work  is  profusely  illustrated 
and  the  engravings  are  all  splendidly  exe- 
cuted, some  of  them  being  works  of  art.  We 
more  than  commend  the  book  to  our  read- 
ers, even  going  so  far  as  to  urge  them  to 
obtain  it.— Medical  Fortnightly,  April  15, 1892, 


LEA  BROTHERS  &  CO ,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Obstetrics* 
Parvin's  Obstetrics— Second  Edition. 

THE  SCIENCE  AND  ART  OF  OBSTETRICS.  By  The- 
OPHILUS  Parvin,  M.  D.,  LL.  D.,  Professor  of  Obstetrics  and  the  Diseases 
of  Women  and  Children  in  Jefferson  Medical  College,  Philadelphia.  Second 
edition.  In  one  handsome  8vo.  volume  of  70 1  pages,  with  239  engravings 
and  a  colored  plate.    Cloth,  $4.25;  leather,  |5.25. 

sion  of  the  undergraduate.  We  think  this 
feature  is  one  of  the  strongest  in  the  work, 
and  commends   it  especially   to   teachers. 


We  regard  it  as  the  most  valuable  text- 
book for  the  student  of  medicine  yet 
published.  The  author  has  been  a  most  suc- 
cessful teacher  for  a  long  period,  and  the 
discipline  and  training  of  the  lecture-room 
are  ohserved  in  the  clearness  with  which  the 
often  obscure  principles  of  the  science  and  art 
of  obstetrics  are  presented  to  thecomprehen- 


The  present  edition  is  greatly  improved,  and 
embodies  all  the  advances  made  in  this  im- 
portant department  of  medicine  up  to  the 
time  of  its  publication.— jBi(/fa^o  Medical  and 
Surgical  Journal,  December,  1890. 


Playfair's  Midwifery— Seventh  Edition. 

A  TREATISE  ON  THE  SCIENCE  AND  PRACTICE  OF 
Midwifery.  By  W.  S.  Playfair,  M.  D.,  F.  K.  C.  P.,  Professor  of  Ob- 
stetric  Medicine  in  King's  College,  London,  etc.  Fifth  American,  from  the 
seventh  English  edition.  Edited,  with  additions,  by  Egbert  P.  Harris, 
M.  D.  In  one  handsome  octavo  volume  of  664  pages,  with  207  engravings 
and  5  plates.     Cloth,  |4.00;  leather,  $5.00. 

the  time  of  complete  involution  has  had  the 
author's  patient  attention.  The  plates  and 
illustrations,  carefully  studied,  will  teach  the 
scleace  of  midwifery.  The  reader  of  this 
book  will  have  before  him  the  very  latest 
and  best  of  obstetric  practice,  and  also  of  all 
the  coincident  troubles  connected  therewith, 
— Southern  Practitioner,  December,  1889. 

This  work  holds  an  enviable  place  in  all 
medical  colleges  as  a  standard  text-book. 
— The  Cincinnati  Lancet-Clinic,  Nov.  2, 1889, 


Truly  a  wonderful  book ;  an  epitome  of  all 
obstetrical  knowledge,  full,  clear  and  con- 
cise. In  thirteen  years  it  has  reached  seven 
editions.  It  is  perhaps  the  most  popular 
work  of  its  kind  ever  presented  to  the  pro- 
fession. Beginning  with  the  anatomy  and 
physiology  of  the  organs  concerned,  noth- 
ing is  left  unwritten  that  the  practical  ac- 
coucheur should  know.  It  seems  that  every 
conceivable  physiological  or  pathological 
condition  from  the  moment  of  conception  to 


King's  Obstetrics— New  (5th)  Edition.   Just  Ready. 

A  MANUAL  OF  OBSTETRICS.  By  A.  F.  A.  King,  M.  D., 
Professor  of  Obstetrics  and  Diseases  of  Women  in  the  Medical  Department 
of  the  Columbian  University,  Washington,  D.  C,  and  in  the  University  of 


Vermont,  etc.     New  (fifth)  edition, 
of  450  pages,  with  150  illustrations. 

We  cannot  imagine  a  better  manual  for  the 
hard-worked  student;  while  its  clean  and 

Practical  teachings  make  it  invaluable  to  the 
usy  practitioner.  The  illustrations  add 
much  to  the  subject  matter. — The  National 
Medical  Review,  Oct.  1892. 

It  seems  to  be  just  the  handy  reference 
book  physicians  want,  and  they  will  not  do 
without  it.     We  are  also  acquainted   with 


In  one  very  handsome  12mo.  volume 
Cloth,  $2.50. 

teachers  of  obstetrics  who  are  particular  to 
recommend  this  manual  to  their  students, 
and  such  advice  based  upon  personal  ex- 
perience, is  certainly  the  best  encomium  that 
could  be  made.  We  can  heartily  recommend 
this  work  to  all  of  our  readers  as  well  as  to 
students  who  desire  to  acquire  a  practical 
knowledge  of  obstetrics. — The  St.  Louis  Med» 
ical  and  Surgical  Journal,  December,  1892, 


The  Students'  Quiz  Series— Obstetrics,  $1.  See  P.  1. 

LEA  BROTHERS  *  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia. 


Obstetrics  ^  Gx^n^cological  Surgery?, 
Barnes'  Obstetric  Medicine  and  Surgery. 

A  SYSTEM  OF  OBSTETRIC  MEDICINE  AND  SUR- 
gery,  Theoretical  and  Clinical.  For  the  Student  and  the  Practitioner. 
By  Robert  Barnes,  M.D.,  Physician  to  the  General  Lying-in  Hospital, 
London,  and  Fancourt  Barnes,  M.  D.,  Obstetric  Physician  to  St.  Thomas' 
Hospital,  London.  The  Section  on  Embryology  by  Professor  Milnes  Marshall. 
In  one  8vo.  volume  of  872  pp.,  with  231  illus.     Cloth,  |5.00;  leather,  |6.00. 


The  immediate  purpose  of  the  work  is  to 
furnish  a  handbook  of  obstetric  medicine 
and  surgery  for  the  use  of  the  student  and 
practitioner.  It  is  not  an  exaggeration  to 
say  of  the  book  that  it  is  the  best  treatise  in 
the  English  language  yet  published.    Every 


practitioner  who  desires  to  have  the  best 
obstetrical  opinions  of  the  time  in  a  readily 
accessible  and  condensed  form,  ought  to  own 
a  copy  of  the  book. — Journal  of  the  American 
Medical  Association,  June  12, 1886. 


Tait  on  Diseases  of  Women  and  Abdominal  Surgery. 

DISEASES  OF  WOMEN  AND  ABDOMINAL  SURGERY. 

By  Lawson  Tait,  F.  K.  C.  S.,  Professor  of  Gynaecology  in  Queen's  College, 
Birmingham;  late  President  of  the  British  Gynecological  Society;  Fellow 
American  Gynecological  Society.  In  two  octavo  volumes.  Volume  I.,  554 
pages,  62  engravings  and  3  plates.     Cloth,  $3.00.     Volume  II.,  preparing. 


Mr.  Tait  never  writes  anything  that  does 
not  command  attention  by  reason  of  the 
originality  of  his  ideas  and  the  clear  and 
forcible  manner  in  which  they  are  expressed. 
This  is  eminently  true  of  the  present  work. 
Germs  of  trutli  are  thickly  scattered  through- 
out; single,  happily-worded  sentences  ex- 
press what  another  author  would  have 
expanded  into  pages.    Useful  hints  on  the 


technique  of  surgical  operations,  ingenious 
theories  on  pathology,  daring  innovations 
on  long-established  rules — these  succeed  one 
another  with  bewildering  rapidity.  His 
position  has  long  been  assured ;  it  is  hardly 
possible  for  him  to  add  to  his  great  reputa- 
tion as  a  daring  and  original  surgeon. — Amer- 
ican Journal  oj  the  Medical  Sciences^  June, 
1890. 


Landis  on  Labor  and  the  Lying-in  Period. 

THE    MANAGEMENT     OF    LABOR,    AND    OF    THE 

Lying-in  Period.  By  Henry  G.  Landis,  A.M.,  M. D.,  Professor  of 
Obstetrics  and  the  Diseases  of  Women  in  Starling  Medical  College,  Colum- 
bus, O.    In  one  handsome  12mo.  vol.  of  334  pp.,  with  28  illus.    Cloth,  $1.75. 

so  busy,  will  find  when  it  is  in  his  library 
that  it  is  a  book  that  will  frequently  be  taken 
from  its  place  for  consu ltation.--2%e  Physician 


It  is  terse  in  its  style,  complete  in  its  in- 
formation, and  clear  in  its  text.  The  advanced 
student  will  find  it  a  desirable  companion  to 
his  larger  text-books  on  obstetrics;  and  the 
"busy  practitioner,"  as  well  as  he  who  is  not 


and  Surgeon,  May,  1886. 


Herman's  First  Lines  in  Midwifery. 

FIRST   LINES  IN  MIDWIFERY:   A  GUIDE   TO   AT- 

tendance  on  Natural  Labor  for  Medical  Students  and  Midwives. 
By  G.  Ernest  Herman,  M.  B.,  F.  R.  C.  P.,  Obstetric  Physician  to  the 
London  Hospital.  In  one  12mo.  volume  of  198  pages  with  80  illustrations. 
Cloth,  11.25.    Jiid  ready.     See  StudenVs  Series  of  3fam<ah,  at  end. 


LEA  BROTHERS  &  CO.,  706,  708  &  710  Sansom  Street,  Philadelphia, 


Children  #  Jurisp>  ^  Syri^s  of  /Vlanuals> 
Smith  on  Children— Seventh  Edition. 

A  TREATISE  ON  THE  DISEASES  OF  INFANCY  AND 

Childhood.  By  J.  Lewis  Smith,  M.  D.,  Clinical  Professor  of  Diseases  of 
Children  in  BellevueHosp.  Med.  Col.,  N.  Y.  Seventh  edition,  thoroughly  re- 
vised and  rewritten.  Octavo,  881  pages,  51illus.  Cloth,  $4.50;  leather,  $5.50. 

edition  we  note  a  variety  of  changes  in  ac- 


We  have  always  considered  Dr.  Smith's 
book  as  one  of  the  very  best  on  the  subject. 
It  ha.s  always  been  practical— a  field  book, 
theoretical  where  theory  has  been  deduced 
from  practical  experience.  The  very  prac- 
tical character  of  this  book  has  always  ap- 
pealed to  us.  Ono  seldom  fails  to  find  here  a 
practical  suggestion  after  search  in  other 
works  has  been  in  vain.    In  the  seventh 


cordance  with  the  progress  of  the  times.  It 
still  stands  foremost  as  the  American  text- 
book. Its  advice  is  always  conservative  and 
thorough,  and  the  evidence  of  research  has 
long  since  placed  its  author  in  the  front  rank 
of  medical  teachers. — American  Journal  of 
the  Medical  Sciences,  Dec.  1891. 


Taylor's  Medical  Jurisprndence— ^^^tJII^^^e^a^dy^^^- 

A   MANUAL    OF    MEDICAL    JURISPRUDENCE.     By 

Alfred  S.  Taylor,  M.  D.,  Lecturer  on  Medical  Jurisprudence  and  Chem- 
istry in  Guy's  Hospital,  London.  New  American  from  the  twelfth  English 
edition.  Thoroughly  revised  by  Clark  Bell,  Esq.,  of  the  New  York  Bar. 
In  one  octavo  vol.  of  787  pages,  with  56  illus.     Cloth,  $4.50;  leather,  $5.50. 

The  merits  of  this  work  are  well  recog- 
nized, audits  value  as  a  standard  text-book 
for  medical  instruction  and  as  a  trustworthy 
guide  in  medico-legal  emergencies  is  fully 
appreciated.  It  is  enough,  to  assert  with  con- 
fidence that  as  4  manual  upon  the  subj  ect 
of  which  it  treats  it  is  not  excelled  by  any 


other  work  on  medical  jurisprudence  in  the 
English  language.  If  the  medical  practi- 
tioner is  obliged  to  limit  his  literature  upon 
legal  medicine  to  a  single  volume,  he  will 
not  make  a  mistake  if  he  gives  his  preference 
to  this  eleventh  American  edition.— ^05/on 
Medical  and  Surgical  Journal,  Jan.  5, 1893. 


Students'  Series  of  Manuals. 


A  Series  of  Fifteen  Manuals,  for  the  Use  of  Students  and  Practitioners  of  Medicine  and 
Surgery,  written  by  eminent  Teachers  or  Examiners,  and  issued  in  pocket-size  12mo.  vol- 
umes of  800-540  pages,  richly  illustrated  and  at  alow  price.  The  following  volumes  are 
now  ready:  ItU ff's  Manual  of  Chemistry,  $2.00;  Hermas^s  First  Lines  in  Midwifery,  $1.25; 
Treves'  Manual  of  Surgery,  hj  various  writers,  in  three  volumes,  per  set,  $6.00;  Bell's 
Comparative  Anatomy  and  Physiology,  $2.00;  Gould's  Surgical  Diagnosis,  $2.00;  Robert- 
son's Physiological  Physics,  $2.00 ;  Bruce's  Materia  Medica  and  Therapeutics  (4th  edition), 
$1.50 ;  Power's  Human  Physiology  (2d  edition),  $1.50;  Clarke  and  Lockv^^ood's  Dissectors' 
Manual,  $L50;  Ralfe's  Clinical  Chemistry,  $1.50;  Treves'  Surgical  Applied  Anatomy, 
$2.00;  Ff.ppkr's  Surgical  Pathology,  $2.00;  and  Ki^FHia^s  Elements  of  Histology  {Uh  edition), 
$1.75.    For  detailed  Catalogue,  address  the  Publishers. 

Series  of  Clinical  Manuals. 

A  collection  of  authoritative  monographs  on  important  clinical  subjects  in  a  cheap  and 

f>ortable  form.  The  volumes  contain  about  550  pages  and  are  freely  illustrated  by  chromo- 
ithographs  and  woodcuts.  The  following  volumes  are  now  ready :  Yeo  on  Food  in  Health 
and  Disease,  $2.00 ;  Broadbent  on  the  Pulse,  $1.75  ;  Carter  &  Frost's  Ophthalmic  Surgery, 
$2.25;  Hutchinson  on  Syphilis,  $2.25';  Marsh  on  the  Joints,  $2  00;  Owen  on  Surgical 
Diseases  of  Children,  $2,00;  Morris  on  Surgical  Diseases  of  the  Kidneys,  $^2.25;  Pick  on 
Fractures  and  Dislocations.  $2,00;  Butlin  on  the  Tongue,  $3.50;  Treves  on  Intestinal 
Obstruction,  $2.00;  and  Savage  on  Insanity  and  Allied  Neuroses,  $2.00.  For  detailed  Cata- 
logue, address  the  Publishers. 

The  Students'  Quiz  Series — Diseases  of  children,  $1.   see  p.  1. 
LEA  BROTHERS  &  CO.,  706,  708  <S  710  Sansom  Street,  Philadelphia.     / 


yi^dical  Periodicals  and  Combinations* 


■  HE  student  cannot  begin  too  early  in  his  course  a  habit  of  reading 
current  medical  literature.  In  this  way  he  will  best  acquire  an 
intelligent  interest  in  the  vital  questions  of  his  profession,  secure 
a  vast  fund  of  information  which  will  constantly  supplement  the 
knowledge  gained  from  text-books,  and  become  familiar  with  the 
approved  methods  of  calling  public  attention  to  such  additions  as  he  may 
make  to  medical  science  during  his  professional  life.  For  these  purposes  the 
following  periodicals  are  most  admirably  adapted: 

THE  MEDICAL  NEWS  (Weekly,  $4.00  per  Annum). 

The  News  contains  each  week  twenty-eight  quarto  pages,  comprising 
original  articles,  clinical  lectures  and  notes  on  practical  advances,  latest 
hospital  methods,  summaries  of  progress  condensed  from  the  best  medical 
journals  of  the  world,  full  abstracts  of  important  articles,  able  editorials  on 
current  topics,  book  reviews,  medical  correspondence  from  important  cen- 
tres, and  news  items  of  interest.  Published  for  fifty  years,  The  News  is 
familiar  with  the  needs  of  medical  men  and  the  best  methods  of  meeting 
them. 

THE  AMERICAN  JOURNAL  OF  THE   MEDICAL   SCIENCES 
(Monthly,  $4.00  per  Annum). 

The  American  Journal  is  a  medical  magazine  affording,  in  the  112 
pages  of  each  issue,  ample  space  for  elaborate  original  articles  on  important 
medical  discoveries,  discriminating  reviews  on  valuable  medical  literature, 
and  classified  summaries  of  progress.  According  to  the  highest  literary 
authority  of  the  profession,  ' '  from  this  file  alone,  were  all  other  publica- 
tions of  the  press  for  the  last  fifty  years  destroyed,  it  would  be  possible  to 
reproduce  the  great  majority  of  the  real  contributions  of  the  world  to 
medical  science  during  that  period." 

COMMUTATION  RATE. 

Taken  together.  The  Journal  and  News  form  a  peculiarly  useful 
combination,  and  afford  their  readers  the  assurance  that  nothing  of  value 
in  the  progress  of  medical  matters  shall  escape  attention.  To  lead  every 
reader  to  prove  this  personally  the  commutation  rate  has  been  placed  at  the 
exceedingly  low  figure  of  $7.50. 

SPECIAL  COMBINATION  OFFERS. 

The  Medical  News  Visiting  List  (regular  price,  $1.25),  or  The 
Year-Book  of  Treatment  (regular  price,  $1.50),  will  be  furnished  to  ad- 
vance-paying subscribers  to  either  or  both  of  these  periodicals  for  75  cents 
apiece;  or  Journal,  News,  Visiting  List  and  Year-Book,  $8.50.  Circulars 
free  on  application.  * 

L^A  BROTHERS  8i  CO,  706,  708  S^  710  Sansom  Street,  Philadelphia. 


THE  LIBRARY 

UNIVERISTY  OF  CALIFORNIA,  SAN  FRANCISCO 
(415)  476-2335 

THIS  BOOK  IS  DUE  ON  THE  LAST  DATE  STAMPED  BELOW 


Books  not  returned  on  time  are  subject  to  fines  according  to  the  Library 
Lending  Code.  A  renewal  may  be  made  on  certain  materials.  For  details 
consult  Lending  Code. 


FE,^  -  5  199? 
HETUHNED 

JAN  2  8  1993 


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